Price Stickiness and Macroeconomics

Noah Smith has a classically snide rejoinder to Stephen Williamson’s outrage at Noah’s Bloomberg paean to price stickiness and to the classic Ball and Maniw article on the subject, an article that provoked an embarrassingly outraged response from Robert Lucas when published over 20 years ago. I don’t know if Lucas ever got over it, but evidently Williamson hasn’t.

Now to be fair, Lucas’s outrage, though misplaced, was understandable, at least if one understands that Lucas was so offended by the ironic tone in which Ball and Mankiw cast themselves as defenders of traditional macroeconomics – including both Keynesians and Monetarists – against the onslaught of “heretics” like Lucas, Sargent, Kydland and Prescott that he just stopped reading after the first few pages and then, in a fit of righteous indignation, wrote a diatribe attacking Ball and Mankiw as religious fanatics trying to halt the progress of science as if that was the real message of the paper – not, to say the least, a very sophisticated reading of what Ball and Mankiw wrote.

While I am not hostile to the idea of price stickiness — one of the most popular posts I have written being an attempt to provide a rationale for the stylized (though controversial) fact that wages are stickier than other input, and most output, prices — it does seem to me that there is something ad hoc and superficial about the idea of price stickiness and about many explanations, including those offered by Ball and Mankiw, for price stickiness. I think that the negative reactions that price stickiness elicits from a lot of economists — and not only from Lucas and Williamson — reflect a feeling that price stickiness is not well grounded in any economic theory.

Let me offer a slightly different criticism of price stickiness as a feature of macroeconomic models, which is simply that although price stickiness is a sufficient condition for inefficient macroeconomic fluctuations, it is not a necessary condition. It is entirely possible that even with highly flexible prices, there would still be inefficient macroeconomic fluctuations. And the reason why price flexibility, by itself, is no guarantee against macroeconomic contractions is that macroeconomic contractions are caused by disequilibrium prices, and disequilibrium prices can prevail regardless of how flexible prices are.

The usual argument is that if prices are free to adjust in response to market forces, they will adjust to balance supply and demand, and an equilibrium will be restored by the automatic adjustment of prices. That is what students are taught in Econ 1. And it is an important lesson, but it is also a “partial” lesson. It is partial, because it applies to a single market that is out of equilibrium. The implicit assumption in that exercise is that nothing else is changing, which means that all other markets — well, not quite all other markets, but I will ignore that nuance – are in equilibrium. That’s what I mean when I say (as I have done before) that just as macroeconomics needs microfoundations, microeconomics needs macrofoundations.

Now it’s pretty easy to show that in a single market with an upward-sloping supply curve and a downward-sloping demand curve, that a price-adjustment rule that raises price when there’s an excess demand and reduces price when there’s an excess supply will lead to an equilibrium market price. But that simple price-adjustment rule is hard to generalize when many markets — not just one — are in disequilibrium, because reducing disequilibrium in one market may actually exacerbate disequilibrium, or create a disequilibrium that wasn’t there before, in another market. Thus, even if there is an equilibrium price vector out there, which, if it were announced to all economic agents, would sustain a general equilibrium in all markets, there is no guarantee that following the standard price-adjustment rule of raising price in markets with an excess demand and reducing price in markets with an excess supply will ultimately lead to the equilibrium price vector. Even more disturbing, the standard price-adjustment rule may not, even under a tatonnement process in which no trading is allowed at disequilibrium prices, lead to the discovery of the equilibrium price vector. Of course, in the real world trading occurs routinely at disequilibrium prices, so that the “mechanical” forces tending an economy toward equilibrium are even weaker than the standard analysis of price-adjustment would suggest.

This doesn’t mean that an economy out of equilibrium has no stabilizing tendencies; it does mean that those stabilizing tendencies are not very well understood, and we have almost no formal theory with which to describe how such an adjustment process leading from disequilibrium to equilibrium actually works. We just assume that such a process exists. Franklin Fisher made this point 30 years ago in an important, but insufficiently appreciated, volume Disequilibrium Foundations of Equilibrium Economics. But the idea goes back even further: to Hayek’s important work on intertemporal equilibrium, especially his classic paper “Economics and Knowledge,” formalized by Hicks in the temporary-equilibrium model described in Value and Capital.

The key point made by Hayek in this context is that there can be an intertemporal equilibrium if and only if all agents formulate their individual plans on the basis of the same expectations of future prices. If their expectations for future prices are not the same, then any plans based on incorrect price expectations will have to be revised, or abandoned altogether, as price expectations are disappointed over time. For price adjustment to lead an economy back to equilibrium, the price adjustment must converge on an equilibrium price vector and on correct price expectations. But, as Hayek understood in 1937, and as Fisher explained in a dense treatise 30 years ago, we have no economic theory that explains how such a price vector, even if it exists, is arrived at, and even under a tannonement process, much less under decentralized price setting. Pinning the blame on this vague thing called price stickiness doesn’t address the deeper underlying theoretical issue.

Of course for Lucas et al. to scoff at price stickiness on these grounds is a bit rich, because Lucas and his followers seem entirely comfortable with assuming that the equilibrium price vector is rationally expected. Indeed, rational expectation of the equilibrium price vector is held up by Lucas as precisely the microfoundation that transformed the unruly field of macroeconomics into a real science.

JKH on the Keynesian Cross and Accounting Identities

Since beginning this series of posts about accounting identities and their role in the simple Keynesian model, I have received a lot of comments from various commenters, but none has been more persistent, penetrating, and patient in his criticisms than JKH, and I have to say that he has forced me to think very carefully, more carefully than I had ever done before, about my objections to forcing the basic Keynesian model to conform to the standard national income accounting identities. So, although we have not (yet?) reached common ground about how to understand the simple Keynesian model, I can say that my own understanding of how the model works (or doesn’t) is clearer than it was when the series started, so I am grateful to JKH for engaging me in this discussion, even though it has gone on a lot longer than I expected, or really wanted, it to.

In response to my previous post in the series, JKH offered a lengthy critical response. Finding his response difficult to understand and confusing, I wrote a rejoinder that prompted JKH to write a series of further comments. Being preoccupied with a couple of other posts and life in general, I was unable to respond to JKH until now. Given the delay in my response, I decided to respond to JKH in a separate post. I start with JKH’s explanation of how an increase in investment spending is accounted for.

First, the investment injection creates income that accrues to the factors of production – labor and capital. This works through cost accounting. The price at which the investment good is sold covers all costs – including the cost of capital. That said, the price may not cover the theoretical “hurdle rate” for the cost of capital. But that is a technical detail. The equity holders earn some sort of actual residual return, positive or negative. So in the more general sense, the actual cost of capital is accounted for.

So the investment injection creates an equivalent amount of income.

No one says that investment expenditure will not generate an equivalent amount of income; what is questionable is whether the income accrues to factors of production instantaneously. JKH maintains that cost accounting ensures that the accrual is instantaneous, but the recording of a bookkeeping entry is not the same as the receipt of income by households, whose consumption and savings decisions are the key determinant of income adjustments in the Keynesian model. See the tacit assumption in the sentence immediately following.

Consider the effect at the moment the income is fully accrued to the factors of production – before anything else happens.

I understand this to mean that income accrues to factors of production the instant expenditure is booked by the manufacturer of the investment goods; otherwise, I don’t understand why this occurs “before anything else happens.” In a numerical example, JKH posits an increase in investment spending of 100, which triggers added production of 100. For purposes of this discussion, I stipulate that there is no lag between expenditure and output, but I don’t accept that income must accrue to workers and owners of the firm instantaneously as output occurs. Most workers are paid per unit of time, wages being an hourly rate based on the number of hours credited per pay period, and salaries being a fixed amount per pay period. So there is no immediate and direct relationship between worker input into the production process and the remuneration received. The additional production associated with the added investment expenditure and production may or may not be associated with any additional payments to labor depending on how much slack capacity is available to firms and on how the remuneration of workers employed in producing the investment goods is determined.

That amount of income must be saved by the macroeconomy – other things equal. We know this because no new consumer goods or services are produced in this initial standalone scenario of a new investment injection. Therefore, given that saving in the generic sense is income not used to purchase consumer goods and services, this new income created by an assumed investment injection must be saved in the first instance.

Since it is quite conceivable (especially if there is unused capacity available to the firm) that producing new investment goods will not change the total remuneration received by (or owed to) workers in the current period, all additional revenue collected by the firm accruing entirely to the owners of the firm, revenue that might not be included in the next scheduled dividend payment by the firm to shareholders, I am not persuaded that it is unreasonable to assume that there is a lag between expenditure on goods and services and the accrual of income to factors of production. At any rate, whether the firm’s revenue is instantaneously transmuted into household income does not seem to be a question that can be answered in only one way.

What the macroeconomy “must” do is an interesting question, but in the basic Keynesian model, income is earned by households, and it is households, not an abstraction called the macroeconomy, that decide how much to consume and how much to save out of their income. So, in the Keynesian model, regardless of the accounting identities, the relevant saving activity – the saving activity specified by the marginal propensity to save — is the saving of households. That doesn’t mean that the model cannot be extended or reconstructed to allow for saving to be carried out by business firms or by other entities, but that is not how the model, at its most basic level, is set up.

So at this incipient stage before the multiplier process starts, S equals I. That’s before the marginal propensity to consume or save is in motion.

One’s eyes may roll at this point, since the operation of the MPC includes the complementary MPS, and the MPS is a saving function that also operates as the multiplier iterates with successive waves of income creation and consumption.

I understand these two sentences to be an implicit concession that the basic Keynesian model is not being presented in the way it is normally presented in textbooks, a concession that accords with my view that the basic Keynesian model does not always dovetail with the national income identities. Lipsey and I say: don’t impose the accounting identities on the Keynesian model when they are at odds; JKH says reconfigure the basic Keynesian model so that it is consistent with the accounting identities. Where JKH and I may perhaps agree is that the standard textbook story about the adjustment process following a change in spending parameters, in which unintended inventory accumulation corresponding to the frustration of individual plans plays a central role, does not follow from the basic Keynesian model.

So one may ask – how can these apparently opposing ideas be reconciled – the contention that S equals I at a point when the multiplier saving dynamic hasn’t even started?

The investment injection results in an equivalent quantity of income and saving as described earlier. I think you question this off the top while I have claimed it must be the case. But please suspend disbelief for purposes of what I want to describe next, because given that assumed starting point, this should at least reinforce the idea that S = I at all times following that same assumption for the investment injection.

It must be the case, if you define income and expenditure to be identical. If you define them so that they are not identical, which seems both possible and reasonable, then savings and investment are also not identical.

So now assume that the first round of the multiplier math works and there is an initial consumption burst of quantity 66, representing the MPC effect on the income of 100 that was just newly created.

And correspondingly there is new saving of 33.

A pertinent question then is how this gets reflected in income accounting.

As a simplification, assume that the factors of the investment good production who received the new income of 100 are the ones who spend the 66.

So the economy has earned 100 in its factors of investment good production capacity and has now spent 66 in its MPC capacity.

Recall that at the investment injection stage considered on its own, before the multiplier starts to work, the economy saved 100.

Yes, that’s fine if income does accrue simultaneously with expenditure, but that depends on how one chooses to define and measure income, and I don’t feel obligated to adopt the standard accounting definition under all circumstances. (And is it really the case that only one way of defining income is countenanced by accountants?) At any rate, in my first iteration of the lagged model, I specified the lag so that income was earned by households at the end of the period with consumption becoming a function of income in the preceding period. In that setup, the accounting identities were indeed satisfied. However, even with the lag specified that way, the main features of the adjustment process stressed in textbook treatments – frustrated plans, and involuntary inventory accumulation or decumulation – were absent.

Then, in the first stage of the multiplier, the economy spent 66 on consumption. For simplicity of exposition, I’ve assumed those who initially saved were the ones who then spent (I.e. the factors of investment production) But no more income has been assumed to be earned by them. So they have dissaved 66 in the second stage. At the same time, those who produced the 66 of consumer goods have earned 66 as factors of production for those consumer goods. But the consumer goods they produced have been purchased. So there are no remaining consumer goods for them to purchase with their income of 66. And that means they have saved 66.

Therefore, the net saving result of the first round of the multiplier effect is 0.

Thus an MPS of 1/3 has resulted in 0 incremental saving for the macroeconomy. That is because the opening saving of 100 by the factors of production for the investment good has only been redistributed as cumulative saving as between 33 for the investment good production factors and 66 for the consumer good production factors. So the amount of cumulative S still equals the amount of original S, which equals I. And the important observation is that the entire quantity of saving was created originally and at the outset as equivalent to the income earned by the factors of the investment good production.

There is no logical problem here given the definitional imputation of income to households in the initial period before any payments to households have actually been made. However, the model has to be reinterpreted so that household consumption and savings decisions are a function of income earned in the previous period.

Each successive round of the multiplier features a similar combination of equal dissaving and saving.

The result is that cumulative saving remains constant at 100 from the outset and I = S remains in tact always.

The important point is that an original investment injection associated with a Keynesian multiplier process accounts for all the macroeconomic saving to come out of that process, and the MPS fallout of the MPC sequence accounts for none of it.

That is fine, but to get that result, you have to amend the basic Keynesian model or make consumption a function the previous period’s income, which is consistent with what I showed in my first iteration of the lagged model. But that iteration also showed that savings has a somewhat different meaning from the meaning usually attached to the term, saving or dissaving corresponding to a passive accumulation of funds associated with income exceeding or falling short of what it was expected to be in a given period.

JKH followed up this comment with another one explaining how, within the basic Keynesian model, a change in investment (or in some other expenditure parameter) causes a sequence of adjustments from the old equilibrium to a new equilibrium.

Assume the economy is at an alleged equilibrium point – at the intersection of a planned expenditure line with the 45 degree line.

Suppose planned investment falls by 100. Again, assume MPC = 2/3.

The scenario is one in which investment will be 100 lower than its previous level (bearing in mind we are referring to the level of investment flows here).

Using comparable logic as in my previous comment, that means that both I and S drop by 100 at the outset. There is that much less investment injected and saving created as a result of the economy not operating at a counterfactual level of activity equal to its previous pace.

So expenditure drops by 100 – and that considered just on its own can be represented by a direct vertical drop from the previous equilibrium point down to the planning line.

But as I have said before, such a point is unrealizable in fact, because it lies off the 45 degree line. And that corresponds to the fact that I of 100 generates S of 100 (or in this case a decline in I from previous levels means a decline in S from previous levels). So what happens is that instead of landing on that 100 vertical drop down point, the economy combines (in measured effect) that move with a second move horizontally to the left, where it lands on the 45 degree line at a point where both E and Y have declined by 100. This simply reflects the fact that I = S at all times as described in my previous comment (which again I realize is a contentious supposition for purposes of the broader discussion).

Actually, it is clear that being off the 45-degree line is not a matter of possibility in any causal or behavioral sense, but is simply a matter of how income and expenditure are defined. With income and expenditure suitably defined, income need not equal expenditure. As just shown, if one wants to define income and expenditure so that they are equal at all times, a temporal adjustment process can be derived if current consumption is made a function of income in the previous period (presumably with an implicit behavioral assumption that households expect to earn the same income in the current period that they earned in the previous period). The adjustment can be easily portrayed in the familiar Keynesian cross, provided that the lag is incorporated into the diagram by measuring E(t) on the vertical axis and measures Y(t-1) on the horizontal axis. The 45-degree line then represents the equilibrium condition that E(t) = Y(t-1), which implies (given the implicit behavioral assumption) that actual income equals expected income or that income is unchanged period to period. Obviously, in this setup, the economy can be off the 45-degree line. Following a change in investment, an adjustment process moves from the old expenditure line to the new one continuing in stepwise fashion from the new expenditure line to the 45-degree line and back in successive periods converging on the point of intersection between the new expenditure line and the 45-degree line.

This happens in steps representable by discrete accounting. Common sense suggests that a “plan” can consist of a series of such discrete steps – in which case there is a ratcheting of reduced investment injections down the 45 degree line – or a plan can consist of a single discrete step depending on the scale or on the preference for stepwise analysis. The single discrete step is the clearest way to analyse the accounting record for the economics.

There is no such “plan” in the model, because no one foresees where the adjustment is leading; households assume in each period that their income will be what it was in the previous period, and firms produce exactly what consumers demand without change in inventories. However, all expenditure planned at the beginning of each period is executed (every household remaining on its planned expenditure curve), but households wind up earning less than expected in each period. Suitably amended, I consider this statement to be consistent with Lipsey’s critique of standard textbook expositions of the Keynesian cross adjustment process wherein the adjustment to a new equilibrium is driven by the frustration of plans.

Finally, some brief responses to JKH’s comments on handling lags.

I’m going to refer to standard accounting for Y as Y and the methodology used in the post as LGY (i.e. “Lipsey – Glasner income” ).

Then:

E ( t ) = Y ( t )

E ( t ) = LGY ( t +1)

Standard accounting recognizes income in the time period in which it is earned.

LGY accounting recognizes income in the time period in which it is paid in cash.

Consider the point in table 1 where the MPC propensity factor drops from .9 to .8. . . .

In the first iteration, E is 900 ( 100 I + 800 C ) but LGY is 1000.

Household saving is shown to be 200.

Here is how standard accounting handles that:

First, a real world example. Suppose a US corporation listed on a stock exchange reports its financial results at the end of each calendar quarter. And suppose it pays its employees once a month. But for each month’s work it pays them at the start of the next month.

Then there is no way that this corporation would report it’s December 31 financial results without showing a liability on its balance sheet for the employee compensation earned in December but not yet paid by December 31. . . .

In effect, the employees have loaned the corporation one months salary until that loan is repaid in the next accounting period.

The corporation will properly list a liability on its balance sheet for wages not yet paid. This may be a “loan in effect,” but employees don’t receive an IOU for the unpaid wages because the wages are not yet due. I am no tax expert, but I am guessing that a liability to pay taxes on the wages owed to, but not yet received by, employees is incurred until the wages are paid, notwithstanding whatever liability is recorded on the books of the corporation. A worker employed in 2014, but not paid until 2015, will owe taxes on his 2015, not 2014, tax return. A “loan in effect” is not the same as an actual payment.

This is precisely what is happening at the macro level in the LGY lag example.

So the standard national income accounting would show E = Y = 900, with a business liability of 900 at the end of the period. Households would have a corresponding financial asset of 900.

The “financial asset” in question is a fiction. There is a claim, but the claim at the end of the period has not fallen due, so it represents a claim to an expected future payment. I expect to get a royalty check next month, for copies of my book sold last year. I don’t consider that I have received income until the check arrives from my publisher, regardless of how the publisher chooses to record its liability to me on its books. And I will not pay any tax on books sold in 2014 until 2016 when I file my 2015 tax return. And I certainly did not consider the expected royalties as income last year when the books were sold. In fact, I don’t know — and never will — when in 2014 the books were sold.

Back at the beginning of that same period, business repaid the prior period liability of 1000 to households. But they received cash revenue of 900 during the period. So as the post says, business cash would have declined by 100 during the period.

This component of 100 when received by households is part of a loan repayment in effect. This does not constitute a component of standard income accounting Y or S for households. This sort of thing is captured In flow of funds accounting.

Just as LGY is the delayed payment of Y earned in the previous period, LGS overstates S by the difference between LGY and Y.

For example, when E is 900, LGY is 1000 and Y is 900. LGS is 200 while S is 100.

So under regular accounting, this systematic LG overstatement reflects the cash repayment of a loan – not the differential receipt of income and saving.

That is certainly a possible interpretation of the assumptions being made, but obviously there are alternative interpretations that are completely consistent with workings of the basic Keynesian model.

And another way of describing this is that households earn Y of 900 and get paid in the same period in the form of a non-cash financial asset of 900, which is in effect a loan to business for the amount of cash that business owes to households for the income the latter have already earned. That loan is repaid in the next period.

Again, I observe that “payments in effect” are being created to avoid working with and measuring actual payments as they take place. I have no problem with such “payments in effect,” but that does not mean that the the magnitudes of interest can be measured in only one way.

There are several ironies in the comparison of LG accounting with standard accounting.

First, using standard accounting in no way impedes the analysis of cash flow lags. In fact, this is the reason for separate balance sheet and flow of funds accounting – so as not to conflate cash flow analysis with the earning of income when there are clear separations between the earning of income and the cash payments to the recipients of that income. The 3 part framework is precise in its treatment of such situations.

Not sure where the irony is. In any event, I don’t see how the 3 part framework adds anything to our understanding of the Keynesian model.

Second, in the scenario constructed for the post, there is no logical connection between a delayed income payment of 1000 and a decision to ramp down consumption propensity. Why would one choose to consume less because an income payment is systematically late? If that was the case, one would ramp down consumption every time a payment was delayed. But every such payment is delayed in this model. Changes in consumption propensity cannot logically be a systematic function of a systematic lag – or consumption propensity would systematically approach 0, which is obviously nonsensical.

This seems to be a misunderstanding of what I wrote. I never suggested that the lag between expenditure and income is connected (logically or otherwise) to the reduction in the marginal propensity to consume. A lag is necessary for there to be a sequential rather than an instantaneous adjustment process to a parameter change in the model, such as a reduced marginal propensity to consume. There is no other connection.

Third, my earlier example of a corporation that delayed an income payment from December until January is a stretch on reality. Corporations have no valid reason to play such cash management games that span accounting periods. They must account for legitimate liabilities that are outstanding when proceeding to the next accounting period.

I never suggested that corporations are playing a game. Wage payments, royalty and dividend payments are made according to fixed schedules, which may not coincide with the relevant time period for measuring economic activity. Fiscal years and calendar years do not always coincide.

Shorter term intra period lags may still exist – as within a one month income payment cycle. But again, so what? There cannot be systemic behavior to reduce consumption propensity due to systematic lags. Moreover, a lot of people get paid every 2 weeks. But that is not even the relevant point. Standard accounting handles any of these issues even at the level of internal management accounting accruals between external financial reporting dates.

I never suggested that the propensity to consume is related to the lag structure in the model. The propensity to consume determines the equilibrium; the lag structure determines the sequence of adjustments, following a change in a spending parameter, from one equilibrium to another.

PS I apologize for this excessively long — even by my long-winded and verbose standards — post.

The Verbally Challenged John Taylor Strikes Again

John Taylor, tireless self-promoter of “rules-based monetary policy” (whatever that means), inventor of the legendary Taylor Rule, and very likely the next Chairman of the Federal Reserve Board if a Republican is elected President of the United States in 2016, has a history of verbal faux pas, which I have been documenting not very conscientiously for almost three years now.

Just to review my list (for which I make no claim of exhaustiveness), Professor Taylor was awarded the Hayek Prize of the Manhattan Institute in 2012 for his book First Principles: Five Keys to Restoring America’s Prosperity. The winner of the prize (a cash award of $50,000) also delivers a public Hayek Lecture in New York City to a distinguished audience consisting of wealthy and powerful and well-connected New Yorkers, drawn from the city’s financial, business, political, journalistic, and academic elites. The day before delivering his public lecture, Professor Taylor published a teaser as an op-ed in that paragon of journalistic excellence the Wall Street Journal editorial page. (This is what I had to say when it was published.)

In his teaser, Professor Taylor invoked Hayek’s Road to Serfdom and his Constitution of Liberty to explain the importance of the rule of law and its relationship to personal freedom. Certainly Hayek had a great deal to say and a lot of wisdom to impart on the subjects of the rule of law and personal freedom, but Professor Taylor, though the winner of the Hayek Prize, was obviously not interested enough to read Hayek’s chapter on monetary policy in The Constitution of Liberty; if he had he could not possibly have made the following assertions.

Stripped of all technicalities, this means that government in all its actions is bound by rules fixed and announced beforehand—rules which make it possible to foresee with fair certainty how the authority will use its coercive powers in given circumstances and to plan one’s individual affairs on the basis of this knowledge. . . .

Rules for monetary policy do not mean that the central bank does not change the instruments of policy (interest rates or the money supply) in response to events, or provide loans in the case of a bank run. Rather they mean that they take such actions in a predictable manner.

But guess what. Hayek took a view rather different from Taylor’s in The Constitution of Liberty:

[T]he case against discretion in monetary policy is not quite the same as that against discretion in the use of the coercive powers of government. Even if the control of money is in the hands of a monopoly, its exercise does not necessarily involve coercion of private individuals. The argument against discretion in monetary policy rests on the view that monetary policy and its effects should be as predictable as possible. The validity of the argument depends, therefore, on whether we can devise an automatic mechanism which will make the effective supply of money change in a more predictable and less disturbing manner than will any discretionary measures likely to be adopted. The answer is not certain.

Now that was bad enough – quoting Hayek as an authority for a position that Hayek explicitly declined to take in the very source invoked by Professor Taylor. But that was just Professor Taylor’s teaser. Perhaps it got a bit garbled in the teasing process. So I went to the Manhattan Institute website and watched the video of the entire Hayek Lecture delivered by Professor Taylor. But things got even worse in the lecture – much worse. I mean disastrously worse. (This is what I had to say after watching the video.)

Taylor, while of course praising Hayek at length, simply displayed an appalling ignorance of Hayek’s writings and an inability to comprehend, or a carelessness so egregious that he was unable to properly read, the title — yes, the title! — of a pamphlet written by Hayek in the 1970s, when inflation was reaching the double digits in the US and much of Europe. The pamphlet, entitled Full Employment at any Price?, was an argument that the pursuit of full employment as an absolute goal, with no concern for price stability, would inevitably lead to accelerating inflation. The title was chosen to convey the idea that the pursuit of full employment was not without costs and that a temporary gain in employment at the cost of higher inflation might well not be worth it. Professor Taylor, however, could not even read the title correctly, construing the title as prescriptive, and — astonishingly — presuming that Hayek was advocating the exact policy that the pamphlet was written to confute.

Perhaps Professor Taylor was led to this mind-boggling misinterpretation by a letter from Milton Friedman, cited by Taylor, complaining about Hayek’s criticism in the pamphlet in question of Friedman’s dumb 3-perceent rule, to which criticism Friedman responded in his letter to Hayek. But Professor Taylor, unable to understand what Hayek and Friedman were arguing about, bewilderingly assumed that Friedman was criticizing Hayek’s advocacy of increasing the rate of inflation to whatever level was needed to ensure full employment, culminating in this ridiculous piece of misplaced condescension.

Well, once again, Milton Friedman, his compatriot in his cause — and it’s good to have compatriots by the way, very good to have friends in his cause. He wrote in another letter to Hayek – Hoover Archives – “I hate to see you come out, as you do here, for what I believe to be one of the most fundamental violations of the rule of law that we have, namely, discretionary activities of central bankers.”

So, hopefully, that was enough to get everybody back on track. Actually, this episode – I certainly, obviously, don’t mean to suggest, as some people might, that Hayek changed his message, which, of course, he was consistent on everywhere else.

And all of this wisdom was delivered by Professor Taylor in his Hayek Lecture upon being awarded the Hayek Prize. Well done, Professor Taylor, well done.

Then last July, in another Wall Street Journal op-ed, Professor Taylor replied to Alan Blinder’s criticism of a bill introduced by House Republicans to require the Fed to use the Taylor Rule as its method for determining what its target would be for the Federal Funds rate. The title of the op-ed was “John Taylor’s reply to Alan Blinder,” and the subtitle was “The Fed’s ad hoc departures from rule-based monetary policy has [sic!] hurt the economy.” When I pointed out the grammatical error, and wondered whether the mistake was attributable to Professor Taylor or stellar editorial writers employed by the Wall Street Journal editorial page, David Henderson, a frequent contributor to the Journal, wrote a comment to assure me that it was certainly not Professor Taylor’s mistake. I took Henderson’s word for it. (Just for the record, the mistake is still there, you can look it up.)

But now there’s this. In today’s New York Times, there is an article about how, in an earlier era, criticism of the Fed came mainly from Democrats complaining about money being too tight and interests rates too high, while now criticism comes mainly from Republicans complaining that money is too easy and interest rates too low. At the end of the article we find this statement from Professor Taylor:

Practical experience and empirical studies show that checklist-free medical care is wrought with dangers just as rules-free monetary policy is,” Mr. Taylor wrote in a recent defense of his proposal.

There he goes again. Here are five definitions of “wrought” from the online Merriam-Webster dictionary:

1:  worked into shape by artistry or effort <carefully wrought essays>

2:  elaborately embellished :  ornamented

3:  processed for use :  manufactured <wrought silk>

4:  beaten into shape by tools :  hammered —used of metals

5:  deeply stirred :  excited —often used with up <gets easily wrought up over nothing>

Obviously, what Professor Taylor meant to say is that medical care is “fraught” (rhymes with “wrought”) with dangers, but some people just can’t be bothered with pesky little details like that, any more than winners of the Hayek Prize can be bothered with actually reading the works of Hayek to which they refer in their Hayek Lecture. Let’s just hope that if Professor Taylor’s ambition to become Fed Chairman is realized, he’ll be a little bit more attentive to, say, the position of decimal points than he is to the placement of question marks and to the difference in meaning between words that sound almost alike.

PS I see that the Manhattan Institute has chosen James Grant as the winner of the 2015 Hayek Prize for his book America’s Forgotten Depression. I’m sure that 2015 Hayek Lecture will be far more finely wrought grammatically and stylistically than the 2012 Hayek Lecture, but, judging from book for which the prize was awarded, I am not overly optimistic that it will make a great deal more sense than the 2012 Hayek Lecture, but that is not a very high bar to clear.

Milton Friedman, Monetarism, and the Great and Little Depressions

Brad Delong has a nice little piece bashing Milton Friedman, an activity that, within reasonable limits, I consider altogether commendable and like to engage in myself from time to time (see here, here, here, here, here , here, here, here, here and here). Citing Barry Eichengreen’s recent book Hall of Mirrors, Delong tries to lay the blame for our long-lasting Little Depression (aka Great Recession) on Milton Friedman and his disciples whose purely monetary explanation for the Great Depression caused the rest of us to neglect or ignore the work of Keynes and Minsky and their followers in explaining the Great Depression.

According to Eichengreen, the Great Depression and the Great Recession are related. The inadequate response to our current troubles can be traced to the triumph of the monetarist disciples of Milton Friedman over their Keynesian and Minskyite peers in describing the history of the Great Depression.

In A Monetary History of the United States, published in 1963, Friedman and Anna Jacobson Schwartz famously argued that the Great Depression was due solely and completely to the failure of the US Federal Reserve to expand the country’s monetary base and thereby keep the economy on a path of stable growth. Had there been no decline in the money stock, their argument goes, there would have been no Great Depression.

This interpretation makes a certain kind of sense, but it relies on a critical assumption. Friedman and Schwartz’s prescription would have worked only if interest rates and what economists call the “velocity of money” – the rate at which money changes hands – were largely independent of one another.

What is more likely, however, is that the drop in interest rates resulting from the interventions needed to expand the country’s supply of money would have put a brake on the velocity of money, undermining the proposed cure. In that case, ending the Great Depression would have also required the fiscal expansion called for by John Maynard Keynes and the supportive credit-market policies prescribed by Hyman Minsky.

I’m sorry, but I find this criticism of Friedman and his followers just a bit annoying. Why? Well, there are a number of reasons, but I will focus on one: it perpetuates the myth that a purely monetary explanation of the Great Depression originated with Friedman.

Why is it a myth? Because it wasn’t Friedman who first propounded a purely monetary theory of the Great Depression. Nor did the few precursors, like Clark Warburton, that Friedman ever acknowledged. Ralph Hawtrey and Gustav Cassel did — 10 years before the start of the Great Depression in 1919, when they independently warned that going back on the gold standard at the post-World War I price level (in terms of gold) — about twice the pre-War price level — would cause a disastrous deflation unless the world’s monetary authorities took concerted action to reduce the international monetary demand for gold as countries went back on the gold standard to a level consistent with the elevated post-War price level. The Genoa Monetary Conference of 1922, inspired by the work of Hawtrey and Cassel, resulted in an agreement (unfortunately voluntary and non-binding) that, as countries returned to the gold standard, they would neither reintroduce gold coinage nor keep their monetary reserves in the form of physical gold, but instead would hold reserves in dollar or (once the gold convertibility of sterling was restored) pound-denominated assets. (Ron Batchelder and I have a paper discussing the work of Hawtrey and Casssel on the Great Depression; Doug Irwin has a paper discussing Cassel.)

After the short, but fierce, deflation of 1920-21 (see here and here), when the US (about the only country in the world then on the gold standard) led the world in reducing the price level by about a third, but still about two-thirds higher than the pre-War price level, the Genoa system worked moderately well until 1928 when the Bank of France, totally defying the Genoa Agreement, launched its insane policy of converting its monetary reserves into physical gold. As long as the US was prepared to accommodate the insane French gold-lust by permitting a sufficient efflux of gold from its own immense holdings, the Genoa system continued to function. But in late 1928 and 1929, the Fed, responding to domestic fears about a possible stock-market bubble, kept raising interest rates to levels not seen since the deflationary disaster of 1920-21. And sure enough, a 6.5% discount rate (just shy of the calamitous 7% rate set in 1920) reversed the flow of gold out of the US, and soon the US was accumulating gold almost as rapidly as the insane Bank of France was.

This was exactly the scenario against which Hawtrey and Cassel had been warning since 1919. They saw it happening, and watched in horror while their warnings were disregarded as virtually the whole world plunged blindly into a deflationary abyss. Keynes had some inkling of what was going on – he was an old friend and admirer of Hawtrey and had considerable regard for Cassel – but, for reasons I don’t really understand, Keynes was intent on explaining the downturn in terms of his own evolving theoretical vision of how the economy works, even though just about everything that was happening had already been foreseen by Hawtrey and Cassel.

More than a quarter of a century after the fact, and after the Keynesian Revolution in macroeconomics was well established, along came Friedman, woefully ignorant of pre-Keynesian monetary theory, but determined to show that the Keynesian explanation for the Great Depression was wrong and unnecessary. So Friedman came up with his own explanation of the Great Depression that did not even begin until December 1930 when the Fed allowed the Bank of United States to fail, triggering, in Friedman’s telling, a wave of bank failures that caused the US money supply to decline by a third by 1933. Rather than see the Great Depression as a global phenomenon caused by a massive increase in the world’s monetary demand for gold, Friedman portrayed it as a largely domestic phenomenon, though somehow linked to contemporaneous downturns elsewhere, for which the primary explanation was the Fed’s passivity in the face of contagious bank failures. Friedman, mistaking the epiphenomenon for the phenomenon itself, ignorantly disregarded the monetary theory of the Great Depression that had already been worked out by Hawtrey and Cassel and substituted in its place a simplistic, dumbed-down version of the quantity theory. So Friedman reinvented the wheel, but did a really miserable job of it.

A. C. Pigou, Alfred Marshall’s student and successor at Cambridge, was a brilliant and prolific economic theorist in his own right. In his modesty and reverence for his teacher, Pigou was given to say “It’s all in Marshall.” When it comes to explaining the Great Depression, one might say as well “it’s all in Hawtrey.”

So I agree that Delong is totally justified in criticizing Friedman and his followers for giving such a silly explanation of the Great Depression, as if it were, for all intents and purposes, made in the US, and as if the Great Depression didn’t really start until 1931. But the problem with Friedman is not, as Delong suggests, that he distracted us from the superior insights of Keynes and Minsky into the causes of the Great Depression. The problem is that Friedman botched the monetary theory, even though the monetary theory had already been worked out for him if only he had bothered to read it. But Friedman’s interest in the history of monetary theory did not extend very far, if at all, beyond an overrated book by his teacher Lloyd Mints A History of Banking Theory.

As for whether fiscal expansion called for by Keynes was necessary to end the Great Depression, we do know that the key factor explaining recovery from the Great Depression was leaving the gold standard. And the most important example of the importance of leaving the gold standard is the remarkable explosion of output in the US beginning in April 1933 (surely before expansionary fiscal policy could take effect) following the suspension of the gold standard by FDR and an effective 40% devaluation of the dollar in terms of gold. Between April and July 1933, industrial production in the US increased by 70%, stock prices nearly doubled, employment rose by 25%, while wholesale prices rose by 14%. All that is directly attributable to FDR’s decision to take the US off gold, and devalue the dollar (see here). Unfortunately, in July 1933, FDR snatched defeat from the jaws of victory (or depression from the jaws of recovery) by starting the National Recovery Administration, whose stated goal was (OMG!) to raise prices by cartelizing industries and restricting output, while imposing a 30% increase in nominal wages. That was enough to bring the recovery to a virtual standstill, prolonging the Great Depression for years.

I don’t say that the fiscal expansion under FDR had no stimulative effect in the Great Depression or that the fiscal expansion under Obama in the Little Depression had no stimulative effect, but you can’t prove that monetary policy is useless just by reminding us that Friedman liked to assume (as if it were a fact) that the demand for money is highly insensitive to changes in the rate of interest. The difference between the rapid recovery from the Great Depression when countries left the gold standard and the weak recovery from the Little Depression is that leaving the gold standard had an immediate effect on price-level expectations, while monetary expansion during the Little Depression was undertaken with explicit assurances by the monetary authorities that the 2% inflation target – in the upper direction, at any rate — was, and would forever more remain, sacred and inviolable.

Why Theories of National Income Based on Accounting Identities Are Nonsensical and Error-Ridden, Part IV

In my previous post, I tried to relate the discussion of accounting identities to the familiar circular-flow diagram with injections into and leakages out of the flows of income, expenditure and output. My hopes that framing the discussion in terms of injections and leakages, with investment viewed as an injection into, and savings as a withdrawal out of, the flows of income and expenditure would help clarify my position about accounting identities were disappointed, as defenders of those accounting identities were highly critical of the injections-leakages analogy, launching a barrage of criticism at my argument that the basic macroeconomic model of income determination should not be understood in terms of the income-expenditure or the investment-savings identities.

I think that criticism of the injections-leakages analogy was, for the most part, misplaced and a based on a misunderstanding of what I have been aiming to do, but much of the criticism was prompted by my incomplete or inadequate explanation of my reasoning. So, before continuing with my summary of Lipsey’s essay on the subject, on which this series is based, I need to address at least some of the points that have been made by my (and Lipsey’s) various critics. In the course of doing so, I believe it will be helpful if I offer a revised version of Lipsey’s Table 1, which I reproduced in part III of this series.

First, I am not saying that the standard accounting identities are wrong. Definitions are neither right nor wrong, but they may be useful or not useful depending on the context. In everyday conversation, we routinely ascribe one of many possible meanings to particular words used by selecting one of the many possible definitions as that which is most likely to make an entire sequence of words – a phrase, a clause, or a sentence – meaningful. Our choice of which definition to use is generally determined by the context in which the word appears. Choosing one definition over another doesn’t mean that others are not valid, just that the others would not work as well or at all in the context in which the word in question appears. Working with an inappropriate definition in a given context can lead, as we all know from personal experience, to confusion, misunderstanding and error. Defining savings and investment to be equal in every state of the world is certainly possible, and doing so is not invalid, but doing so is not necessarily useful in the context of formulating a macroeconomic theory of income determination.

There are two reasons why defining savings and investment to be identically equal in all states of the world is not useful in a macroeconomic theory of income. First, if we define savings and investment (or income and expenditure) to be identically equal, we can’t solve, either algebraically or graphically, the system of equations describing the model for a unique equilibrium. According to the model, aggregate expenditure is assumed to be a function of income, but if income and expenditure are identical, expenditure is simply identical to itself, so the system of equations described by the model collapses onto the 45-degree line representing the expenditure-income identity.

Second, even if we interpret the equality of income and expenditure as an ex ante equilibrium condition, while asserting that identity between income and expenditure must always hold ex post, the ex post definitional equality tells us nothing about the adjustment process that restores equilibrium when, owing to some parameter change that disturbs a pre-existing equilibrium, the ex ante equilibrium condition does not hold. For a dynamic adjustment path to take the model from one equilibrium to another via a sequence of discrete adjustments, the model must incorporate some lags. Without lags, the adjustment would be instantaneous, and the model would move from its old equilibrium to a new equilibrium in one fell swoop. But in the course of a sequence of partial adjustments, savings and investment will typically have to be defined by the model so that they are not equal, and this will be reflected in the implied course of savings and investment if the model is worked out period-by-period. Or if you were to observe the Phillips machine (a hydraulic macroeconomic model built by A. W. Phillips of Phillips Curve fame) in action, you could actually see that the savings and investment flows were of unequal magnitudes as machine responded to a change in the settings and moved from one hydraulic equilibrium to another.

It is a common mistake, and the primary object of Richard Lipsey’s scorn in his essay, to attribute causal significance to the savings-investment identity, as if it were the force of the identity itself that guided the dynamic adjustment, when, in reality, the identity, which can always be recovered if one does all the necessary accounting and classifies all the transactions according to the accounting conventions, is irrelevant to the adjustment path. Doing the accounting does not explain how the model moves from the old to a new equilibrium; it just assures us that nothing has been omitted from a final description of what has happened. Rather, the causal mechanism driving the adjustment process can be described using the intuitive idea that income changes because there are injections (in the form of investment) into the income and expenditure flows and leakages (in the form of savings) out of those flows, and when the injections and leakages are unequal in magnitude, the discrepancy between the injections and the leakages causes a corresponding change in the income and expenditure flows.

One commenter pointed out that, even in the numerical example (taken from Lipsey’s essay) that I gave in my earlier post, the sequence of adjustments preserved the definitional equality between savings and investment and income and expenditure, even though the verbal explanation of the adjustment process showed that the equality of savings and investment required a rather forced interpretation of the meaning of savings: the difference between the cash balance expected at the end of a period and the actual cash balance at the end of the period. This peculiar interpretation of savings and its equality with investment reflected the way that Lipsey chose to introduce a lag between expenditure and income into the model: by assuming that income was disbursed by businesses to households at the end of the period in which households provide services to businesses. The income received at the end of one period is then used to finance consumption expenditures and savings in the following period.

I should have pointed out that if one made the trivial adjustment in the expenditure-income lag, so that incomes earned in one period are not at the end of the current period, but at the beginning of the following period, then income and expenditure and savings and investment would not remain equal over the course of the adjustment from the old to the new equilibrium. The sequence of adjustments under the alternative assumption is shown in Table 1 below.

Of course, if we assume that there is a one-period lag between expenditure and income, one could define something called total savings, which would be household savings plus business savings, where business savings is defined as the difference between cash held by businesses at the end of the current period and cash held by businesses at the end of the previous period. And total savings is identically equal to investment. However, it is important to bear in mind that from the point of view of the simple income-expenditure model, the relevant causal variable in determining equilibrium is not total savings, but household savings.

Why do I say that household savings, not business savings, is the relevant causal factor in determining equilibrium income in the simple income-expenditure model? The reason should be obvious: the solution for equilibrium in the simple income-expenditure model is Y = A/(1 – MPC), where A represents the autonomous component of consumption plus planned investment by business firms and MPC is the marginal propensity to consume by households, so that (1 – MPC) is the marginal propensity to save (MPS) . . . by households!

In this setup, business savings is a pure residual adjusting to make up the difference between household savings and investment. When household savings exceeds investment, businesses accumulate their holdings of cash, and when investment is greater than household saving, businesses reduce their accumulate cash. The operation of the banking system might be relevant at this point, but that analysis would take this discussion to a whole new level, which I am not going to get started on at this point.

I will close at this point by just saying that I think that I have provided an answer to the following comment on my previous post asking what is gained by introducing an alternative set of definitions of saving and investment under which savings and investment are equal only in equilibrium, but not otherwise:

But let’s just say you have a system of accounts where definitions are different and saving is different from investment. I can do a mathematical transformation to a new set of variables in which standard identities hold. What is the point of writing so much? Absolutely nothing.

The point of course is that by defining savings and investment so that they are equal only in equilibrium, we now have a system of two linear equations in two unknowns that can be solved for a unique solution, something that cannot be done if savings and investment are identically equal. Second, when we have defined savings and investment so that they can be unequal, but define their equality to be a condition of equilibrium, we can write the following dynamic relationships characterizing the system:

dY/dt = 0 <=> I = S

dY/dt > 0 <=> I > S

dY/dt < 0 <=> I < S

where I and S are defined under the behavioral assumptions in this example as actual investment by businesses and saving by households. The precise definition of I and S would depend, in each particular case, on the specific behavioral assumptions about the underlying lag structure of the model for that particular case. The definitional equality of total savings and investment has no causal significance, but simply reflects the fact that total savings is defined in such a way that it must equal investment.

The definitional equality of savings and investment, as Scott Sumner has observed, is exactly analogous to the quantity identity MV ≡ PY, when V is treated not as the reciprocal of the amount of money demanded as a fraction of income — which is to say as a measurable magnitude understood to be a function of specifiable independent variables — but simply as a residual whose value, by definition, must always be identically equal to PY/M. The quantity identity, lacking being consistent with all possible states of the world, because V is defined not as an independent variable, but as a mere residual. The quantity identity is therefore of no use in describing the dynamic process of adjustment to a change in the quantity of money or what in telling us what are the causes of such a process.

UPDATE (3/29/15): In writing a response to Jamie’s comment, I realized that in the third paragraph after the table above, I misstated the relationship between business savings and the difference between investment and household savings. I have made the correction, and apologize for not being more careful.

Of Bathtubs, Drains, and Faucets

I was planning to write another installment in my series of posts on the savings-investment identity in which I have been working through and summarizing Richard Lipsey’s essay “The Foundations of the Theory of National Income.” Perhaps I will get to my next installment later this week. If not, then I hope to do so early next week. But it occurred to me that the best way to explain why saving is not identical to investment is by framing the discussion in terms of the familiar circular-flow schematic model of income and expenditure. The accompanying diagram is a typical representation of the circular-flow model, with a government sector (government spending and taxes) and a foreign sector (exports and imports) included in addition to just circular_flow_modelinvestment and saving.

As indicated by the arrows in the diagram, investment, government spending, and exports are added to the circular flow while savings, taxes and imports are withdrawn from the circular. In the conventional terminology, investment, government spending and exports are injections, and savings, taxes and imports are leakages. And, of course, a basic property of the model is that injections and leakages are equal. It is only in the simplest model, with no government and with no foreign sector, so that there is just one injection (investment) and one leakage (saving), in which the familiar equality between investment and savings holds.

So the question that I want to ask now is simply this: is the equality in the simple one-sector model between injections (investment) and leakages (savings) an equality that may or may not be true, or is it an identity that must necessarily be satisfied in all places and at all times?

Well, rather than try to argue this through in terms of abstract economic or accounting reasoning, let’s think about it in terms of a simple physical analogy, one that we could actually demonstrate for ourselves in our own homes. So think of a bathtub with some water in it. Depending on the size of the bathtub and the amount of water in the bathtub, the water will reach some uniform height in the bathtub. Let’s call that uniform water level an equilibrium. It’s an equilibrium, because if that’s all the water there is in the bathtub, and we don’t let any water out of the bathtub, and, for purposes of our little thought experiment, we ignore any evaporation, that water level will persist indefinitely, with no tendency to change. No water in, no water out, and you have a constant water level. In other words, with no injections and no leakages, the water level of the bathtub is stable; it does not change. The water level is in equilibrium.

But if you turn on the faucet and water starts to flow into the bathtub, the water level will start to rise. As long as water is being injected into the bathtub, the water level will keep rising, and the water level will not be in equilibrium. However, if you unplug the drain to the bathtub, water will start flowing out of the bathtub. What happens to the water level? That depends on whether water is leaking out of the bathtub through the drain faster than water is being injected into the bath tub through the faucet. If injections are greater than leakages, the water level will rise, and if leakages are greater than injections, the water level will fall. And if, by chance or design, injections are exactly equal to leakages, then the water level will be stable and back in equilibrium. Thus, the condition for a stable water level is that injections be exactly equal to leakages. When injections into, and leakages from, the bathtub are equal, the water level of the bathtub is in equilibrium. When injections are greater than leakages, the water level rises, and when leakages are greater than injections the water level falls.

I think all that is pretty elementary, and I am guessing that if you look in any textbook treatment of injections and leakages in the circular flow of income, you will find a similar story about the effect of a difference between injections and leakages on the level of income. (Check out the Wikipedia article on the circular flow of income, especially the section on equilibrium.)

So, if you believe that investment and savings are identically equal, please tell me whether you also believe that injections and leakages are identically equal. And if you do believe that injections and leakages are identically equal, please explain to me what the difference is between the circular-flow-of-income model with injections and leakages identically equal in equilibrium or out of equilibrium and the bathtub model in which the water level can change only insofar as injections and leakages are not equal.

Why Theories of National Income Based on Accounting Identities Are Nonsensical and Error-Ridden, Part III

In my previous post, I argued that an accounting identity, which tells us that two expressions are defined to be the same, must hold in every state of the world, and therefore could not be disproved by any conceivable observation. So if I define savings and investment (or income and expenditure) to be the same thing, I am simply restricting my semantic description of the world, I am not restricting in any way the set of observable states of the world that conform to my semantic convention. An accounting identity therefore has no empirical content, which means that the accounting identity between savings and investment cannot explain the process by which a macroeconomic model adjusts to a parametric change in the model, traversing from a pre-existing equilibrium with savings and investment being equal to a new equilibrium with savings and investment equal.

In his paper, “The Foundations of the Theory of National Income,” which I am attempting to summarize and explain in this series of posts, R. G. Lipsey provides a numerical example of such an adjustment path. And it will be instructive to follow that path in some detail. The key point about this model is the assumption that households decide how much to save and consume in the current period based on the disposable income received in the previous period. The assumption that all receipts of the business firms are paid out to owners and providers of factor services at the end of each period is a behavioral assumption (not an accounting identity) that rules out any change in the retained earnings held by firms. If firms were accumulating financial assets, then their payments to households would not match their receipts. The following simple model reflects a one-period lag (known as a Robertsonian lag) between household earnings and household consumption.

C(t) = aY(t-1) (behavioral assumption)

I(t) = I* (behavioral assumption)

E(t) ≡ C(t) + I(t) (accounting identity)

Y(t) ≡ C(t) + S(t) (accounting identity)

Y(t) = E(t) (behavioral assumption)

Y(t-1) = Y(t) (equilibrium condition)

Assume that the economy starts off with a = .9 and I(t) = 100. The system is easily solved for E = Y = 1000, with C = 900 and I = 100. Savings, which is the difference between Y and C, is 100, just equal to I. The definition of saving will have to be fleshed out further below. Now assume that there is a parametric change in a (the marginal propensity to consume) to .8 from .9. This change causes equilibrium income to fall from 1000 to 500. By assumption, investment is constant, so that in the new equilibrium saving remains equal to 100. The change in income is reflected in a drop in consumption from 900 to 400. But given the one-period lag between earnings and expenditure, we can follow how the system changes over time, moving closer and closer to the new equilibrium in each successive period, as shown in the following table.

Consider the following questions.

First, in the course of this period-by-period adjustment, will there be any unplanned investment?

Second, in this example, the parametric change — an increase in the propensity of households to save — may be described as an increase in planned savings by households. Planned investment is unchanged. With planned savings greater than planned investment, will the household plans to increase savings be frustrated (implying positive or negative unplanned savings) as alleged in proposition 3 in the list of erroneous propositions provided earlier in the first installment in this series (see appendix below).

The answer to the first question is: not necessarily. There is nothing to prevent us from assuming that all firms correctly anticipate the reduction in consumer demand, so that production falls along with consumption with no change in inventories. It is not necessary to assume that firms can foresee the future; it could be that all consumption is in the form of services, or that production is undertaken only in response to consumer orders. With inventories unchanged, there is no unplanned investment.

The answer to the second question is that it depends on what is meant by unplanned savings. Unplanned savings could mean that households wind up saving an amount other than the amount that they had intended to save at the beginning of the period; households intended to save 200 at the beginning of period 0, but because their income turned out to be only 900, instead of 1000, in period 0, household savings, under the accounting identity, is only 100 instead of 200. However, households intended to consume 800 in period 0, and that is the amount that they actually consumed. The only sense in which households did not execute their intended plans is that household income in period 0 was less than households had expected. Lipsey calls this a distinction between plans in the point sense, and plans in the schedule sense. In this scenario, while plans in the schedule sense are carried out, plans in the point sense are not, because households do not end up at the point on their consumption functions that they had expected to be on.

So the equilibrium condition above that income does not change from one period to the next can be restated as follows: the system is in equilibrium when planned savings equals realized savings. Planned savings is the unconsumed portion of households’ expected income, which is the income households earned in the previous period. The definition embodies a specific behavioral hypothesis about how households formulate their expectations of income in the future.

S_p_(t) ≡ Y(t-1) – C(t).

Realized savings is the unconsumed portion of households’ actual income in the current period. It can be written as

S_r_(t) ≡ Y(t) – C(t).

Or restated differently yet again, the equilibrium condition is that actual disposable income in period t equals expected disposable income in period t.

Let’s flesh out the behavioral assumptions behind this model in a bit more detail. Business firms disburse income to households (owners and providers of factor services) at the end of each period. Households decide how much to save and consume in the upcoming period after receiving their incomes from firms at the close of the previous period. Savings are in the form of bond purchases made at the start of the period. Based on the consumption and savings plans formulated by households at the start of the new period, firms decide how much output to produce and how much labor to hire to produce that output, firms immediately notifying households how many hours they will work in the upcoming period. However, households are committed to the consumption plans already made at the beginning of the period, so they must execute those plans even if the incomes earned during the period are less than anticipated.

In our example, by choosing to increase their savings to 200 through bond purchases at the beginning of the upcoming period, while reducing consumption from 900 to 800, households cause business firms to reduce output from 1000 to 900 (investment being unchanged), and to reduce employment (measured in terms of total hours worked) by 11.1%. After buying bonds equal to 200, households have 800 left in cash, with which they finance their purchases for the rest of the month. So it is not obvious that households were unable to execute any of their plans  during the period. However, at the end of the period, households receive only 900 in income from business firms, so although households did buy bonds equal to 200 at the start of the period, they carry over only 900 in cash into the next period, not 1000 as expected. Thus, realized savings are only 100 instead of 200, because household cash holding at the endo f the period turned out to be 100 less than expected. Nevertheless, it is difficult to identify any plan to save that was frustrated, inasmuch as households did purchase bonds equal to 200 at the beginning of the period, and did reduce consumption as planned. As Lipsey puts it:

[W]hether or not the actual real plans laid by households are frustrated depends on what plans households lay, i.e., it depends on our behaviour assumption, not on our definitions. If we assume that households make point plans about their bonds, and schedules plans about their transactions and precautionary balances, then no frustration of plans occurs.

If the statement quoted in (3) [see appendix below] is meant to have empirical content, it depends on a very specific hypothesis about households’ savings plans. These plans must be made in the point and not in the schedule sense, and the plans must include not only additions to the stock of income-earning assets, but also point-plans concerning transactions balances even though the household does not now know what level of transactions the balances will be required to facilitate. . . .

[W]e are now in a position to see what is wrong with statement (2), that actual savings must always equal actual investment, and statement (5), which draws the analogy with demand and supply analysis. Consider statement (2) first.

In the General Theory, Keynes stressed the fact that savings and investment decisions are made by different groups and that there is thus, no reason why planned investment should equal planned savings. [It has been argued] that, although plans can differ, actual realised saving must always be equal to actual realised investment, and, therefore, when planned savings does not equal planned investment, either the plans of savers, or of investors, must be frustrated. Of course, it is quite possible to define savings and investment so that they are the same thing, but it is a basic error to equate the magnitude so defined with the magnitude about which savers actually lay plans. Since ex post S and I as defined bear no relation to the magnitudes about which savers actually make plans, we can deduce nothing about what happens when ex ante S is not equal to ex ante I from the fact that we chose to use the terms ex post S and ex post I to refer to a single, and different, magnitude. The basic error arises from the assumption that households and firms make plans about the same magnitude when they are planning their savings and investment. The traditional theory defines investment as goods produced and not sold to households (= capital goods plus changes in inventories). According to our theory of the behaviour of firms, this is what firms do lay plans about: they plan to add so many capital goods and so many inventories to their existing holdings. The theory then says I ≡ S, and , thus, builds in the implicit assumption that households lay plans about the same magnitude. But according to the standard theory of household behaviour, they do not do so! Households, not subject to money illusion, are assumed to wish to lay aside a certain quantity of real purchasing power which is either used to increase the holdings of cash or used to purchase bonds. There is nothing in the standard theory of household behaviour that leads us to hypothesise that households care whether or not there exists – produced but unconsumed – a physical stock of goods which is the counterpart of the money they have laid aside. Indeed why should they? All they are assumed to care about is the potential real purchasing power of their savings, and this depends only on the amount of money saved, the present price level, and the expected future price level.

This is one of the keys to the whole present confusion: households lay plans about a magnitude that is different from the one that firms lay plans about. Firms plan to have produced and unconsumed a certain quantity of goods, while households plan to leave unspent a certain quantity of purchasing power. This means that it is quite possible for planned investment to differ from planned savings and to have both sets of plans fulfilled so that actual, realized investment differs from actual realized savings. [footnote: Now, of course, we mean by realised S and I the realised magnitudes about which firms and households are actually laying plans. This, of course, does not interfere with the statistician saying that realised savings is identical with realised investment since he refers to a different magnitude when he speaks of realised savings.]

Now consider another variation of the numerical example in Table 1. Instead of a change in the propensity to consume in period 0, assume instead that planned investment drops from 100 to 0. Starting with period -1, Table 2 displays the same initial equilibrium as in Table 1. Because we make a behavioral hypothesis that inventories do not change, planned and realized investment must be zero in period 0 and in all subsequent periods.

According to the national-income identities, savings must equal zero because investment is zero. But what is the actual behavior that corresponds to zero saving? In period 0, households carried over 1000 in cash from period -1. From that 1000, they used 100 to buy bonds and spent the remainder of their disposable incomes on consumption goods. So households planned to save 100 and consume 900, and it appears that they succeeded in executing their plans. But according to the national-income identities, they failed to execute their plan to save 100, and saved only 0, presumably because there were unintended savings of -100 that cancelled out the planned (and executed) savings of 100. So it appears that we have come up against something of a paradox. Here is Lipsey’s solution of the paradox.

[A]ny definitions are possible if consistently used, but this use of the word “unintended” has nothing to do with intended and unintended behaviour. To preserve the identity we must say that the plans of households were frustrated because a real counterpart of the saving they successfully made was not produced. We may say this if we wish, but the danger is that we will think we have said something about the world, and about the actual experiences of households. Indeed, a perusal of established textbooks shows that this confusion has occurred over and over again.

Thus, we conclude that, when we define investment as production not consumed, and savings as income [not consumed] . . . there is no reason why actual savings should not differ from actual investment.

Finally, what about the analogy between savings and investment in macro analysis and demand and supply in micro analysis as in erroneous statement (4) (see appendix)? If we write demand for some good as a function of the price of the good

D = D(p),

and write the supply of some good as a function of the price of the good

S = S(p),

then our equilibrium condition is simply D = S, where D represents desired purchases of the good, and S represents desired sales of the good. Because the act of selling logically entails the activity of purchasing, a purchase and a sale are merely different names for the same thing. So the plans of demanders to buy and the plans of suppliers to sell are plans about the same thing. The plans of demanders to buy and the plans of suppliers to sell cannot be fulfilled simultaneously unless there is an equilibrium in which demand equals supply. The difference between the microeconomic equilibrium in which demand equals supply and the macroeconomic equilibrium in which savings equals investment is that suppliers and demanders in a market are making plans about the same magnitude: sales (aka purchases) of a good. However,

in the national income case the two sets of real plans (savers’ and investors’) are laid about two different magnitudes. Thus the analogy often draw between the two theories in respect of plans and realized quantities is an incorrect one.

Appendix: List of Erroneous Propositions

1 The equilibrium of the basic Keynesian model is given by the intersection of the aggregate demand (i.e., expenditure) function and the 45-degree line representing the accounting identity EY.

2 Although people may try to save different amounts from what people try to invest, savings can’t be different from investment; realized (ex post) savings necessarily always equals realized (ex post) investment.

3 Out of equilibrium, planned savings do not equal planned investment, so it follows from (2) that someone’s plans are being disappointed, and there must be either unplanned savings or dissavings, or unplanned investment or disinvestment

4 The simultaneous fulfilment of the plans of savers and investors occurs only when income is at its equilibrium level just as the plans of buyers and sellers can be simultaneously fulfilled only at the equilibrium price.

5 Whenever savers (households) plan to save an amount different from what investors (business firms) plan to invest, a mechanism operates to ensure that realized savings remain equal to realized investment, despite the attempts of savers and investors to make it otherwise. Indeed, this mechanism is what causes dynamic change in the circular flow of income and expenditure.

6 Since the real world, unlike the simple textbook model, contains a very complex set of interactions, it is not easy to see how savings stay equal to investment even in the worst disequilibrium and the most rapid change.

7 The dynamic behavior of the Keynesian circular flow model in which disequilibrium implies unintended investment or disinvestment can be shown by moving upwards or downwards along the gap between the expenditure function and the 45-degree line in the basic Keynesian model.


About Me

David Glasner
Washington, DC

I am an economist at the Federal Trade Commission. Nothing that you read on this blog necessarily reflects the views of the FTC or the individual commissioners. Although I work at the FTC as an antitrust economist, most of my research and writing has been on monetary economics and policy and the history of monetary theory. In my book Free Banking and Monetary Reform, I argued for a non-Monetarist non-Keynesian approach to monetary policy, based on a theory of a competitive supply of money. Over the years, I have become increasingly impressed by the similarities between my approach and that of R. G. Hawtrey and hope to bring Hawtrey's unduly neglected contributions to the attention of a wider audience.

Enter your email address to follow this blog and receive notifications of new posts by email.

Join 321 other followers


Follow

Get every new post delivered to your Inbox.

Join 321 other followers