Archive for February, 2016

Currency Depreciation and Monetary Expansion Redux

Last week Frances Coppola and I exchanged posts about competitive devaluation. Frances chided me for favoring competitive devaluation, competitive devaluation, in her view, accomplishing nothing in a world of fiat currencies, because exchange rates don’t change. Say, the US devalues the dollar by 10% against the pound and Britain devalues the pound by 10% against the dollar; it’s as if nothing happened. In reply, I pointed out that if the competitive devaluation is achieved by monetary expansion (the US buying pounds with dollars to drive up the value of the pound and the UK buying dollars with pounds to drive up the value of the dollar), the result must be  increased prices in both the US and the UK. Frances responded that our disagreement was just a semantic misunderstanding, because she was talking about competitive devaluation in the absence of monetary expansion; so it’s all good.

I am, more or less, happy with that resolution of our disagreement, but I am not quite persuaded that the disagreement between us is merely semantic, as Frances seems conflicted about Hawtrey’s argument, carried out in the context of a gold standard, which served as my proof text for the proposition that competitive devaluation really is expansionary. On the one hand, she seems to distinguish between the expansionary effect of competitive devaluation relative to gold – Hawtrey’s case – and the beggar-my-neighbor effect of competitive devaluation of fiat currencies relative to each other; on the other hand, she also intimates that even Hawtrey got it wrong in arguing that competitive devaluation is expansionary. Now, much as I admire Hawtrey, I have no problem with criticizing him; it just seems that Frances hasn’t decided whether she does – or doesn’t – agree with him.

But what I want to do in this post is not to argue with Frances, though some disagreements may be impossible to cover up; I just want to explain the relationship between competitive devaluation and monetary expansion.

First some context. One of the reasons that I — almost exactly four years ago – wrote my post about Hawtrey and competitive devaluations (aka currency wars) is that critics of quantitative easing had started to make the argument that the real point of quantitative easing was to gain a competitive advantage over other countries by depreciating – or devaluing – their currencies. What I was trying to show was that if a currency is being depreciated by monetary expansion (aka quantitative easing), then, as Frances now seems – but I’m still not sure – ready to concede, the combination of monetary expansion and currency devaluation has a net expansionary effect on the whole world, and the critics of quantitative easing are wrong. Because the competitive devaluation argument has so often been made together with a criticism of quantitative easing, I assumed, carelessly it appears, that in criticizing my post, Frances was disagreeing with my support of currency depreciation in the context of monetary expansion and quantitative easing.

With that explanatory preface out of the way, let’s think about how to depreciate a fiat currency on the foreign exchange markets. A market-clearing exchange rate between two fiat currencies can be determined in two ways (though there is often a little of both in practice): 1) a currency peg and 2) a floating rate. Under a currency peg, one or both countries are committed to buying and selling the other currency in unlimited quantities at the pegged (official) rate. If neither country is prepared to buy or sell its currency in unlimited quantities at the pegged rate, the peg is not a true peg, because the peg will not withstand a sufficient shift in the relative market demands for the currencies. If the market demand is inconsistent with the quasi-peg, either the pegged rate will cease to be a market-clearing rate, with a rationing system imposed while the appearance of a peg is maintained, or the exchange rate will be allowed to float to clear the market. A peg can be one-sided or two-sided, but a two-sided peg is possible only so long as both countries agree on the exchange rate to be pegged; if they disagree, the system goes haywire. To use Nick Rowe’s terminology, the typical case of a currency peg involves an alpha (or dominant, or reserve) currency which is taken as a standard and a beta currency which is made convertible into the alpha currency at a rate chosen by the issuer of the beta currency.

With floating currencies, the market is cleared by adjustment of the exchange rate rather than currency purchases or sales by the monetary authority to maintain the peg. In practice, monetary authorities generally do buy and sell their currencies in the market — sometimes with, and  sometimes without, an exchange-rate target — so the operation of actual foreign exchange markets lies somewhere in between the two poles of currency pegs and floating rates.

What does this tell us about currency depreciation? First, it is possible for a country to devalue its currency against another currency to which its currency is pegged by changing the peg unilaterally. If a peg is one-sided, i.e., a beta currency is tied to an alpha, the issuer of the beta currency chooses the peg unilaterally. If the peg is two-sided, then the peg cannot be changed unilaterally; the two currencies are merely different denominations of a single currency, and a unilateral change in the peg means that the common currency has been abandoned and replaced by two separate currencies.

So what happens if a beta currency pegged to an alpha currency, e.g., the Hong Kong dollar which pegged to the US dollar, is devalued? Say Hong Kong has an unemployment problem and attributes the problem to Hong Kong wages being too high for its exports to compete in world markets. Hong Kong decides to solve the problem by devaluing their dollar from 13 cents to 10 cents. Would the devaluation be expansionary or contractionary for the rest of the world?

Hong Kong is the paradigmatic small open economy. Its export prices are quoted in US dollars determined in world markets in which HK is a small player, so the prices of HK exports quoted in US dollars don’t change, but in HK dollars the prices rise by 30%. Suddenly, HK exporters become super-profitable, and hire as many workers as they can to increase output. Hong Kong’s unemployment problem is solved.

(Brief digression. There are those who reject this reasoning, because it supposedly assumes that Hong Kong workers suffer from money illusion. If workers are unemployed because their wages are too high relative to the Hong Kong producer price level, why don’t they accept a cut in nominal wages? We don’t know. But if they aren’t willing to accept a nominal-wage cut, why do they allow themselves to be tricked into accepting a real-wage cut by way of a devaluation, unless they are suffering from money illusion? And we all know that it’s irrational to suffer from money illusion, because money is neutral. The question is a good question, but the answer is that the argument for monetary neutrality and for the absence of money illusion presumes a comparison between two equilibrium states. But the devaluation analysis above did not start from an equilibrium; it started from a disequilibrium. So the analysis can’t be refuted by saying that it implies that workers suffer from money illusion.)

The result of the Hong Kong export boom and corresponding increase in output and employment is that US dollars will start flowing into Hong Kong as payment for all those exports. So the next question is what happens to those dollars? With no change in the demand of Hong Kong residents to hold US dollars, they will presumably want to exchange their US dollars for Hong Kong dollars, so that the quantity of Hong Kong dollars held by Hong Kong residents will increase. Because domestic income and expenditure in Hong Kong is rising, some of the new Hong Kong dollars will probably be held, but some will be spent. The increased spending as a result of rising incomes and a desire to convert some of the increased cash holdings into other assets will spill over into increased purchases by Hong Kong residents on imports or foreign assets. The increase in domestic income and expenditure and the increase in import prices will inevitably cause an increase in prices measured in HK dollars.

Thus, insofar as income, expenditure and prices are rising in Hong Kong, the immediate real exchange rate advantage resulting from devaluation will dissipate, though not necessarily completely, as the HK prices of non-tradables including labor services are bid up in response to the demand increase following devaluation. The increase in HK prices and increased spending by HK residents on imported goods will have an expansionary effect on the rest of the world (albeit a small one because Hong Kong is a small open economy). That’s the optimistic scenario.

But there is also a pessimistic scenario that was spelled out by Max Corden in his classic article on exchange rate protection. In this scenario, the HK monetary authority either reduces the quantity of HK dollars to offset the increase in HK dollars caused by its export surplus, or it increases the demand for HK dollars to match the increase in the quantity of HK dollars. It can reduce the quantity of HK dollars by engaging in open-market sales of domestic securities in its portfolio, and it can increase the demand for HK dollars by increasing the required reserves that HK banks must hold against the HK dollars (either deposits or banknotes) that they create. Alternatively, the monetary authority could pay interest on the reserves held by HK banks at the central bank as a way of  increasing the amount of HK dollars demanded. By eliminating the excess supply of HK dollars through one of more of these methods, the central bank prevents the increase in HK spending and the reduction in net exports that would otherwise have occurred in response to the HK devaluation. That was the great theoretical insight of Corden’s analysis: the beggar-my-neighbor effect of devaluation is not caused by the devaluation, but by the monetary policy that prevents the increase in domestic income associated with devaluation from spilling over into increased expenditure. This can only be accomplished by a monetary policy that deliberately creates a chronic excess demand for cash, an excess demand that can only be satisfied by way of an export surplus.

The effect (though just second-order) of the HK policy on US prices can also be determined, because the policy of the HK monetary authority involves an increase in its demand to hold US FX reserves. If it chooses to hold the additional dollar reserves in actual US dollars, the increase in the demand for US base money will, ceteris paribus, cause the US price level to fall. Alternatively, if the HK monetary authority chooses to hold its dollar reserves in the form of US Treasuries, the yield on those Treasuries will tend to fall. A reduced yield on Treasuries will increase the desired holdings of dollars, also implying a reduced US price level. Of course, the US is capable of nullifying the deflationary effect of HK currency manipulation by monetary expansion; the point is that the HK policy will have a (slight) deflationary effect on the US unless it is counteracted.

If I were writing a textbook, I would say that it is left as an exercise for the reader to work out the analysis of devaluation in the case of floating currencies. So if you feel like stopping here, you probably won’t be missing very much. But just to cover all the bases, I will go through the argument quickly. If a country wants to drive down the floating exchange rate between its currency and another currency, the monetary authority can buy the foreign currency in exchange for its own currency in the FX markets. It’s actually not necessary to intervene directly in FX markets to do this, issuing more currency, by open-market operations (aka quantitative easing) would also work, but the effect in FX markets will show up more quickly than if the expansion is carried out by open market purchases. So in the simplest case, currency depreciation is actually just another term for monetary expansion. However, the link between monetary expansion and currency depreciation can be broken if a central bank simultaneously buys the foreign currency with new issues of its own currency while making open-market sales of assets to mop up the home currency issued while intervening in the FX market. Alternatively, it can intervene in the FX market while imposing increased reserve requirements on banks, thereby forcing them to hold the newly issued currency, or by paying banks a sufficiently interest rate on reserves held at the central bank to willingly hold the newly issued currency.

So, it is my contention that there is no such thing as pure currency depreciation without monetary expansion. If currency depreciation is to be achieved without monetary expansion, the central bank must also simultaneously either carry out open-market sales to mop the currency issued in the process of driving down the exchange rate of the currency, or impose reserve requirements on banks, or pay interest on bank reserves, thereby creating an increased demand for the additional currency that was issued to drive down the exchange value of the home currency

Competitive Devaluation Plus Monetary Expansion Does Create a Free Lunch

I want to begin this post by saying that I’m flattered by, and grateful to, Frances Coppola for the first line of her blog post yesterday. But – and I note that imitation is the sincerest form of flattery – I fear I have to take issue with her over competitive devaluation.

Frances quotes at length from a quotation from Hawtrey’s Trade Depression and the Way Out that I used in a post I wrote almost four years ago. Hawtrey explained why competitive devaluation in the 1930s was – and in my view still is – not a problem (except under extreme assumptions, which I will discuss at the end of this post). Indeed, I called competitive devaluation a free lunch, providing her with a title for her post. Here’s the passage that Frances quotes:

This competitive depreciation is an entirely imaginary danger. The benefit that a country derives from the depreciation of its currency is in the rise of its price level relative to its wage level, and does not depend on its competitive advantage. If other countries depreciate their currencies, its competitive advantage is destroyed, but the advantage of the price level remains both to it and to them. They in turn may carry the depreciation further, and gain a competitive advantage. But this race in depreciation reaches a natural limit when the fall in wages and in the prices of manufactured goods in terms of gold has gone so far in all the countries concerned as to regain the normal relation with the prices of primary products. When that occurs, the depression is over, and industry is everywhere remunerative and fully employed. Any countries that lag behind in the race will suffer from unemployment in their manufacturing industry. But the remedy lies in their own hands; all they have to do is to depreciate their currencies to the extent necessary to make the price level remunerative to their industry. Their tardiness does not benefit their competitors, once these latter are employed up to capacity. Indeed, if the countries that hang back are an important part of the world’s economic system, the result must be to leave the disparity of price levels partly uncorrected, with undesirable consequences to everybody. . . .

The picture of an endless competition in currency depreciation is completely misleading. The race of depreciation is towards a definite goal; it is a competitive return to equilibrium. The situation is like that of a fishing fleet threatened with a storm; no harm is done if their return to a harbor of refuge is “competitive.” Let them race; the sooner they get there the better. (pp. 154-57)

Here’s Frances’s take on Hawtrey and me:

The highlight “in terms of gold” is mine, because it is the key to why Glasner is wrong. Hawtrey was right in his time, but his thinking does not apply now. We do not value today’s currencies in terms of gold. We value them in terms of each other. And in such a system, competitive devaluation is by definition beggar-my-neighbour.

Let me explain. Hawtrey defines currency values in relation to gold, and advertises the benefit of devaluing in relation to gold. The fact that gold is the standard means there is no direct relationship between my currency and yours. I may devalue my currency relative to gold, but you do not have to: my currency will be worth less compared to yours, but if the medium of account is gold, this does not matter since yours will still be worth the same amount in terms of gold. Assuming that the world price of gold remains stable, devaluation therefore principally affects the DOMESTIC price level.  As Hawtrey says, there may additionally be some external competitive advantage, but this is not the principal effect and it does not really matter if other countries also devalue. It is adjusting the relationship of domestic wages and prices in terms of gold that matters, since this eventually forces down the price of finished goods and therefore supports domestic demand.

Conversely, in a floating fiat currency system such as we have now, if I devalue my currency relative to yours, your currency rises relative to mine. There may be a domestic inflationary effect due to import price rises, but we do not value domestic wages or the prices of finished goods in terms of other currencies, so there can be no relative adjustment of wages to prices such as Hawtrey envisages. Devaluing the currency DOES NOT support domestic demand in a floating fiat currency system. It only rebalances the external position by making imports relatively more expensive and exports relatively cheaper.

This difference is crucial. In a gold standard system, devaluing the currency is a monetary adjustment to support domestic demand. In a floating fiat currency system, itis an external adjustment to improve competitiveness relative to other countries.

Actually, Frances did not quote the entire passage from Hawtrey that I reproduced in my post, and Frances would have done well to quote from, and to think carefully about, what Hawtrey said in the paragraphs preceding the ones she quoted. Here they are:

When Great Britain left the gold standard, deflationary measure were everywhere resorted to. Not only did the Bank of England raise its rate, but the tremendous withdrawals of gold from the United States involved an increase of rediscounts and a rise of rates there, and the gold that reached Europe was immobilized or hoarded. . . .

The consequence was that the fall in the price level continued. The British price level rose in the first few weeks after the suspension of the gold standard, but then accompanied the gold price level in its downward trend. This fall of prices calls for no other explanation than the deflationary measures which had been imposed. Indeed what does demand explanation is the moderation of the fall, which was on the whole not so steep after September 1931 as before.

Yet when the commercial and financial world saw that gold prices were falling rather than sterling prices rising, they evolved the purely empirical conclusion that a depreciation of the pound had no effect in raising the price level, but that it caused the price level in terms of gold and of those currencies in relation to which the pound depreciated to fall.

For any such conclusion there was no foundation. Whenever the gold price level tended to fall, the tendency would make itself felt in a fall in the pound concurrently with the fall in commodities. But it would be quite unwarrantable to infer that the fall in the pound was the cause of the fall in commodities.

On the other hand, there is no doubt that the depreciation of any currency, by reducing the cost of manufacture in the country concerned in terms of gold, tends to lower the gold prices of manufactured goods. . . .

But that is quite a different thing from lowering the price level. For the fall in manufacturing costs results in a greater demand for manufactured goods, and therefore the derivative demand for primary products is increased. While the prices of finished goods fall, the prices of primary products rise. Whether the price level as a whole would rise or fall it is not possible to say a priori, but the tendency is toward correcting the disparity between the price levels of finished products and primary products. That is a step towards equilibrium. And there is on the whole an increase of productive activity. The competition of the country which depreciates its currency will result in some reduction of output from the manufacturing industry of other countries. But this reduction will be less than the increase in the country’s output, for if there were no net increase in the world’s output there would be no fall of prices.

So Hawtrey was refuting precisely the argument raised  by Frances. Because the value of gold was not stable after Britain left the gold standard and depreciated its currency, the deflationary effect in other countries was mistakenly attributed to the British depreciation. But Hawtrey points out that this reasoning was backwards. The fall in prices in the rest of the world was caused by deflationary measures that were increasing the demand for gold and causing prices in terms of gold to continue to fall, as they had been since 1929. It was the fall in prices in terms of gold that was causing the pound to depreciate, not the other way around

Frances identifies an important difference between an international system of fiat currencies in which currency values are determined in relationship to each other in foreign exchange markets and a gold standard in which currency values are determined relative to gold. However, she seems to be suggesting that currency values in a fiat money system affect only the prices of imports and exports. But that can’t be so, because if the prices of imports and exports are affected, then the prices of the goods that compete with imports and exports must also be affected. And if the prices of tradable goods are affected, then the prices of non-tradables will also — though probably with a lag — eventually be affected as well. Of course, insofar as relative prices before the change in currency values were not in equilibrium, one can’t predict that all prices will adjust proportionately after the change.

To make the point in more abstract terms, the principle of purchasing power parity (PPP) operates under both a gold standard and a fiat money standard, and one can’t just assume that the gold standard has some special property that allows PPP to hold, while PPP is somehow disabled under a fiat currency system. Absent an explanation of why PPP doesn’t hold in a floating fiat currency system, the assertion that devaluing a currency (i.e., driving down the exchange value of one currency relative to other currencies) “is an external adjustment to improve competitiveness relative to other countries” is baseless.

I would also add a semantic point about this part of Frances’s argument:

We do not value today’s currencies in terms of gold. We value them in terms of each other. And in such a system, competitive devaluation is by definition beggar-my-neighbour.

Unfortunately, Frances falls into the common trap of believing that a definition actually tell us something about the real word, when in fact a definition tell us no more than what meaning is supposed to be attached to a word. The real world is invariant with respect to our definitions; our definitions convey no information about reality. So for Frances to say – apparently with the feeling that she is thereby proving her point – that competitive devaluation is by definition beggar-my-neighbour is completely uninformative about happens in the world; she is merely informing us about how she chooses to define the words she is using.

Frances goes on to refer to this graph taken from Gavyn Davies in the Financial Times, concerning a speech made by Stanley Fischer about research done by Fed staff economists showing that the 20% appreciation in the dollar over the past 18 months has reduced the rate of US inflation by as much as 1% and is projected to cause US GDP in three years to be about 3% lower than it would have been without dollar appreciation.Gavyn_Davies_Chart

Frances focuses on these two comments by Gavyn. First:

Importantly, the impact of the higher exchange rate does not reverse itself, at least in the time horizon of this simulation – it is a permanent hit to the level of GDP, assuming that monetary policy is not eased in the meantime.

And then:

According to the model, the annual growth rate should have dropped by about 0.5-1.0 per cent by now, and this effect should increase somewhat further by the end of this year.

Then, Frances continues:

But of course this assumes that the US does not ease monetary policy further. Suppose that it does?

The hit to net exports shown on the above graph is caused by imports becoming relatively cheaper and exports relatively more expensive as other countries devalue. If the US eased monetary policy in order to devalue the dollar support nominal GDP, the relative prices of imports and exports would rebalance – to the detriment of those countries attempting to export to the US.

What Frances overlooks is that by easing monetary policy to support nominal GDP, the US, aside from moderating or reversing the increase in its real exchange rate, would have raised total US aggregate demand, causing US income and employment to increase as well. Increased US income and employment would have increased US demand for imports (and for the products of American exporters), thereby reducing US net exports and increasing aggregate demand in the rest of the world. That was Hawtrey’s argument why competitive devaluation causes an increase in total world demand. Francis continues with a description of the predicament of the countries affected by US currency devaluation:

They have three choices: they respond with further devaluation of their own currencies to support exports, they impose import tariffs to support their own balance of trade, or they accept the deflationary shock themselves. The first is the feared “competitive devaluation” – exporting deflation to other countries through manipulation of the currency; the second, if widely practised, results in a general contraction of global trade, to everyone’s detriment; and you would think that no government would willingly accept the third.

But, as Hawtrey showed, competitive devaluation is not a problem. Depreciating your currency cushions the fall in nominal income and aggregate demand. If aggregate demand is kept stable, then the increased output, income, and employment associated with a falling exchange rate will spill over into a demand for the exports of other countries and an increase in the home demand for exportable home products. So it’s a win-win situation.

However, the Fed has permitted passive monetary tightening over the last eighteen months, and in December 2015 embarked on active monetary tightening in the form of interest rate rises. Davies questions the rationale for this, given the extraordinary rise in the dollar REER and the growing evidence that the US economy is weakening. I share his concern.

And I share his concern, too. So what are we even arguing about? Equally troubling is how passive tightening has reduced US demand for imports and for US exportable products, so passive tightening has negative indirect effects on aggregate demand in the rest of the world.

Although currency depreciation generally tends to increase the home demand for imports and for exportables, there are in fact conditions when the general rule that competitive devaluation is expansionary for all countries may be violated. In a number of previous posts (e.g., this, this, this, this and this) about currency manipulation, I have explained that when currency depreciation is undertaken along with a contractionary monetary policy, the terms-of-trade effect predominates without any countervailing effect on aggregate demand. If a country depreciates its exchange rate by intervening in foreign-exchange markets, buying foreign currencies with its own currency, thereby raising the value of foreign currencies relative to its own currency, it is also increasing the quantity of the domestic currency in the hands of the public. Increasing the quantity of domestic currency tends to raise domestic prices, thereby reversing, though probably with a lag, the effect on the currency’s real exchange rate. To prevent the real-exchange rate from returning to its previous level, the monetary authority must sterilize the issue of domestic currency with which it purchased foreign currencies. This can be done by open-market sales of assets by the cental bank, or by imposing increased reserve requirements on banks, thereby forcing banks to hold the new currency that had been created to depreciate the home currency.

This sort of currency manipulation, or exchange-rate protection, as Max Corden referred to it in his classic paper (reprinted here), is very different from conventional currency depreciation brought about by monetary expansion. The combination of currency depreciation and tight money creates an ongoing shortage of cash, so that the desired additional cash balances can be obtained only by way of reduced expenditures and a consequent export surplus. Since World War II, Japan, Germany, Taiwan, South Korea, and China are among the countries that have used currency undervaluation and tight money as a mechanism for exchange-rate protectionism in promoting industrialization. But exchange rate protection is possible not only under a fiat currency system. Currency manipulation was also possible under the gold standard, as happened when the France restored the gold standard in 1928, and pegged the franc to the dollar at a lower exchange rate than the franc had reached prior to the restoration of convertibility. That depreciation was accompanied by increased reserve requirements on French banknotes, providing the Bank of France with a continuing inflow of foreign exchange reserves with which it was able to pursue its insane policy of accumulating gold, thereby precipitating, with a major assist from the high-interest rate policy of the Fed, the deflation that turned into the Great Depression.

There Is No Intertemporal Budget Constraint

Last week Nick Rowe posted a link to a just published article in a special issue of the Review of Keynesian Economics commemorating the 80th anniversary of the General Theory. Nick’s article discusses the confusion in the General Theory between saving and hoarding, and Nick invited readers to weigh in with comments about his article. The ROKE issue also features an article by Simon Wren-Lewis explaining the eclipse of Keynesian theory as a result of the New Classical Counter-Revolution, correctly identified by Wren-Lewis as a revolution inspired not by empirical success but by a methodological obsession with reductive micro-foundationalism. While deploring the New Classical methodological authoritarianism, Wren-Lewis takes solace from the ability of New Keynesians to survive under the New Classical methodological regime, salvaging a role for activist counter-cyclical policy by, in effect, negotiating a safe haven for the sticky-price assumption despite its shaky methodological credentials. The methodological fiction that sticky prices qualify as micro-founded allowed New Keynesianism to survive despite the ascendancy of micro-foundationalist methodology, thereby enabling the core Keynesian policy message to survive.

I mention the Wren-Lewis article in this context because of an exchange between two of the commenters on Nick’s article: the presumably pseudonymous Avon Barksdale and blogger Jason Smith about microfoundations and Keynesian economics. Avon began by chastising Nick for wasting time discussing Keynes’s 80-year old ideas, something Avon thinks would never happen in a discussion about a true science like physics, the 100-year-old ideas of Einstein being of no interest except insofar as they have been incorporated into the theoretical corpus of modern physics. Of course, this is simply vulgar scientism, as if the only legitimate way to do economics is to mimic how physicists do physics. This methodological scolding is typically charming New Classical arrogance. Sort of reminds one of how Friedrich Engels described Marxian theory as scientific socialism. I mean who, other than a religious fanatic, would be stupid enough to argue with the assertions of science?

Avon continues with a quotation from David Levine, a fine economist who has done a lot of good work, but who is also enthralled by the New Classical methodology. Avon’s scientism provoked the following comment from Jason Smith, a Ph. D. in physics with a deep interest in and understanding of economics.

You quote from Levine: “Keynesianism as argued by people such as Paul Krugman and Brad DeLong is a theory without people either rational or irrational”

This is false. The L in ISLM means liquidity preference and e.g. here …

http://krugman.blogs.nytimes.com/2013/11/18/the-new-keynesian-case-for-fiscal-policy-wonkish/

… Krugman mentions an Euler equation. The Euler equation essentially says that an agent must be indifferent between consuming one more unit today on the one hand and saving that unit and consuming in the future on the other if utility is maximized.

So there are agents in both formulations preferring one state of the world relative to others.

Avon replied:

Jason,

“This is false. The L in ISLM means liquidity preference and e.g. here”

I know what ISLM is. It’s not recursive so it really doesn’t have people in it. The dynamics are not set by any micro-foundation. If you’d like to see models with people in them, try Ljungqvist and Sargent, Recursive Macroeconomic Theory.

To which Jason retorted:

Avon,

So the definition of “people” is restricted to agents making multi-period optimizations over time, solving a dynamic programming problem?

Well then any such theory is obviously wrong because people don’t behave that way. For example, humans don’t optimize the dictator game. How can you add up optimizing agents and get a result that is true for non-optimizing agents … coincident with the details of the optimizing agents mattering.

Your microfoundation requirement is like saying the ideal gas law doesn’t have any atoms in it. And it doesn’t! It is an aggregate property of individual “agents” that don’t have properties like temperature or pressure (or even volume in a meaningful sense). Atoms optimize entropy, but not out of any preferences.

So how do you know for a fact that macro properties like inflation or interest rates are directly related to agent optimizations? Maybe inflation is like temperature — it doesn’t exist for individuals and is only a property of economics in aggregate.

These questions are not answered definitively, and they’d have to be to enforce a requirement for microfoundations … or a particular way of solving the problem.

Are quarks important to nuclear physics? Not really — it’s all pions and nucleons. Emergent degrees of freedom. Sure, you can calculate pion scattering from QCD lattice calculations (quark and gluon DoF), but it doesn’t give an empirically better result than chiral perturbation theory (pion DoF) that ignores the microfoundations (QCD).

Assuming quarks are required to solve nuclear physics problems would have been a giant step backwards.

To which Avon rejoined:

Jason

The microfoundation of nuclear physics and quarks is quantum mechanics and quantum field theory. How the degrees of freedom reorganize under the renormalization group flow, what effective field theory results is an empirical question. Keynesian economics is worse tha[n] useless. It’s wrong empirically, it has no theoretical foundation, it has no laws. It has no microfoundation. No serious grad school has taught Keynesian economics in nearly 40 years.

To which Jason answered:

Avon,

RG flow is irrelevant to chiral perturbation theory which is based on the approximate chiral symmetry of QCD. And chiral perturbation theory could exist without QCD as the “microfoundation”.

Quantum field theory is not a ‘microfoundation’, but rather a framework for building theories that may or may not have microfoundations. As Weinberg (1979) said:

” … quantum field theory itself has no content beyond analyticity, unitarity,
cluster decomposition, and symmetry.”

If I put together an NJL model, there is no requirement that the scalar field condensate be composed of quark-antiquark pairs. In fact, the basic idea was used for Cooper pairs as a model of superconductivity. Same macro theory; different microfoundations. And that is a general problem with microfoundations — different microfoundations can lead to the same macro theory, so which one is right?

And the IS-LM model is actually pretty empirically accurate (for economics):

http://informationtransfereconomics.blogspot.com/2014/03/the-islm-model-again.html

To which Avon responded:

First, ISLM analysis does not hold empirically. It just doesn’t work. That’s why we ended up with the macro revolution of the 70s and 80s. Keynesian economics ignores intertemporal budget constraints, it violates Ricardian equivalence. It’s just not the way the world works. People might not solve dynamic programs to set their consumption path, but at least these models include a future which people plan over. These models work far better than Keynesian ISLM reasoning.

As for chiral perturbation theory and the approximate chiral symmetries of QCD, I am not making the case that NJL models requires QCD. NJL is an effective field theory so it comes from something else. That something else happens to be QCD. It could have been something else, that’s an empirical question. The microfoundation I’m talking about with theories like NJL is QFT and the symmetries of the vacuum, not the short distance physics that might be responsible for it. The microfoundation here is about the basic laws, the principles.

ISLM and Keynesian economics has none of this. There is no principle. The microfoundation of modern macro is not about increasing the degrees of freedom to model every person in the economy on some short distance scale, it is about building the basic principles from consistent economic laws that we find in microeconomics.

Well, I totally agree that IS-LM is a flawed macroeconomic model, and, in its original form, it was borderline-incoherent, being a single-period model with an interest rate, a concept without meaning except as an intertemporal price relationship. These deficiencies of IS-LM became obvious in the 1970s, so the model was extended to include a future period, with an expected future price level, making it possible to speak meaningfully about real and nominal interest rates, inflation and an equilibrium rate of spending. So the failure of IS-LM to explain stagflation, cited by Avon as the justification for rejecting IS-LM in favor of New Classical macro, was not that hard to fix, at least enough to make it serviceable. And comparisons of the empirical success of augmented IS-LM and the New Classical models have shown that IS-LM models consistently outperform New Classical models.

What Avon fails to see is that the microfoundations that he considers essential for macroeconomics are themselves derived from the assumption that the economy is operating in macroeconomic equilibrium. Thus, insisting on microfoundations – at least in the formalist sense that Avon and New Classical macroeconomists understand the term – does not provide a foundation for macroeconomics; it is just question begging aka circular reasoning or petitio principia.

The circularity is obvious from even a cursory reading of Samuelson’s Foundations of Economic Analysis, Robert Lucas’s model for doing economics. What Samuelson called meaningful theorems – thereby betraying his misguided acceptance of the now discredited logical positivist dogma that only potentially empirically verifiable statements have meaning – are derived using the comparative-statics method, which involves finding the sign of the derivative of an endogenous economic variable with respect to a change in some parameter. But the comparative-statics method is premised on the assumption that before and after the parameter change the system is in full equilibrium or at an optimum, and that the equilibrium, if not unique, is at least locally stable and the parameter change is sufficiently small not to displace the system so far that it does not revert back to a new equilibrium close to the original one. So the microeconomic laws invoked by Avon are valid only in the neighborhood of a stable equilibrium, and the macroeconomics that Avon’s New Classical mentors have imposed on the economics profession is a macroeconomics that, by methodological fiat, is operative only in the neighborhood of a locally stable equilibrium.

Avon dismisses Keynesian economics because it ignores intertemporal budget constraints. But the intertemporal budget constraint doesn’t exist in any objective sense. Certainly macroeconomics has to take into account intertemporal choice, but the idea of an intertemporal budget constraint analogous to the microeconomic budget constraint underlying the basic theory of consumer choice is totally misguided. In the static theory of consumer choice, the consumer has a given resource endowment and known prices at which consumers can transact at will, so the utility-maximizing vector of purchases and sales can be determined as the solution of a constrained-maximization problem.

In the intertemporal context, consumers have a given resource endowment, but prices are not known. So consumers have to make current transactions based on their expectations about future prices and a variety of other circumstances about which consumers can only guess. Their budget constraints are thus not real but totally conjectural based on their expectations of future prices. The optimizing Euler equations are therefore entirely conjectural as well, and subject to continual revision in response to changing expectations. The idea that the microeconomic theory of consumer choice is straightforwardly applicable to the intertemporal choice problem in a setting in which consumers don’t know what future prices will be and agents’ expectations of future prices are a) likely to be very different from each other and thus b) likely to be different from their ultimate realizations is a huge stretch. The intertemporal budget constraint has a completely different role in macroeconomics from the role it has in microeconomics.

If I expect that the demand for my services will be such that my disposable income next year would be $500k, my consumption choices would be very different from what they would have been if I were expecting a disposable income of $100k next year. If I expect a disposable income of $500k next year, and it turns out that next year’s income is only $100k, I may find myself in considerable difficulty, because my planned expenditure and the future payments I have obligated myself to make may exceed my disposable income or my capacity to borrow. So if there are a lot of people who overestimate their future incomes, the repercussions of their over-optimism may reverberate throughout the economy, leading to bankruptcies and unemployment and other bad stuff.

A large enough initial shock of mistaken expectations can become self-amplifying, at least for a time, possibly resembling the way a large initial displacement of water can generate a tsunami. A financial crisis, which is hard to model as an equilibrium phenomenon, may rather be an emergent phenomenon with microeconomic sources, but whose propagation can’t be described in microeconomic terms. New Classical macroeconomics simply excludes such possibilities on methodological grounds by imposing a rational-expectations general-equilibrium structure on all macroeconomic models.

This is not to say that the rational expectations assumption does not have a useful analytical role in macroeconomics. But the most interesting and most important problems in macroeconomics arise when the rational expectations assumption does not hold, because it is when individual expectations are very different and very unstable – say, like now, for instance — that macroeconomies become vulnerable to really scary instability.

Simon Wren-Lewis makes a similar point in his paper in the Review of Keynesian Economics.

Much discussion of current divisions within macroeconomics focuses on the ‘saltwater/freshwater’ divide. This understates the importance of the New Classical Counter Revolution (hereafter NCCR). It may be more helpful to think about the NCCR as involving two strands. The one most commonly talked about involves Keynesian monetary and fiscal policy. That is of course very important, and plays a role in the policy reaction to the recent Great Recession. However I want to suggest that in some ways the second strand, which was methodological, is more important. The NCCR helped completely change the way academic macroeconomics is done.

Before the NCCR, macroeconomics was an intensely empirical discipline: something made possible by the developments in statistics and econometrics inspired by The General Theory. After the NCCR and its emphasis on microfoundations, it became much more deductive. As Hoover (2001, p. 72) writes, ‘[t]he conviction that macroeconomics must possess microfoundations has changed the face of the discipline in the last quarter century’. In terms of this second strand, the NCCR was triumphant and remains largely unchallenged within mainstream academic macroeconomics.

Perhaps I will have some more to say about Wren-Lewis’s article in a future post. And perhaps also about Nick Rowe’s article.

HT: Tom Brown

Update (02/11/16):

On his blog Jason Smith provides some further commentary on his exchange with Avon on Nick Rowe’s blog, explaining at greater length how irrelevant microfoundations are to doing real empirically relevant physics. He also expands on and puts into a broader meta-theoretical context my point about the extremely narrow range of applicability of the rational-expectations equilibrium assumptions of New Classical macroeconomics.

David Glasner found a back-and-forth between me and a commenter (with the pseudonym “Avon Barksdale” after [a] character on The Wire who [didn’t end] up taking an economics class [per Tom below]) on Nick Rowe’s blog who expressed the (widely held) view that the only scientific way to proceed in economics is with rigorous microfoundations. “Avon” held physics up as a purported shining example of this approach.
I couldn’t let it go: even physics isn’t that reductionist. I gave several examples of cases where the microfoundations were actually known, but not used to figure things out: thermodynamics, nuclear physics. Even modern physics is supposedly built on string theory. However physicists do not require every pion scattering amplitude be calculated from QCD. Some people do do so-called lattice calculations. But many resort to the “effective” chiral perturbation theory. In a sense, that was what my thesis was about — an effective theory that bridges the gap between lattice QCD and chiral perturbation theory. That effective theory even gave up on one of the basic principles of QCD — confinement. It would be like an economist giving up opportunity cost (a basic principle of the micro theory). But no physicist ever said to me “your model is flawed because it doesn’t have true microfoundations”. That’s because the kind of hard core reductionism that surrounds the microfoundations paradigm doesn’t exist in physics — the most hard core reductionist natural science!
In his post, Glasner repeated something that he had before and — probably because it was in the context of a bunch of quotes about physics — I thought of another analogy.

Glasner says:

But the comparative-statics method is premised on the assumption that before and after the parameter change the system is in full equilibrium or at an optimum, and that the equilibrium, if not unique, is at least locally stable and the parameter change is sufficiently small not to displace the system so far that it does not revert back to a new equilibrium close to the original one. So the microeconomic laws invoked by Avon are valid only in the neighborhood of a stable equilibrium, and the macroeconomics that Avon’s New Classical mentors have imposed on the economics profession is a macroeconomics that, by methodological fiat, is operative only in the neighborhood of a locally stable equilibrium.

 

This hits on a basic principle of physics: any theory radically simplifies near an equilibrium.

Go to Jason’s blog to read the rest of his important and insightful post.


About Me

David Glasner
Washington, DC

I am an economist in the Washington DC area. My research and writing has been mostly on monetary economics and policy and the history of economics. 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 1,299 other followers

Follow Uneasy Money on WordPress.com