Tuesday, September 27, 2011

Quasi-Monetarism: A Second Opinion

(Anush Kapadia, who knows this stuff much better than me, writes in with some comments on the last few posts. I accept this as a friendly amendment, and don't disagree with any of it. I agree with particular enthusiasm with the points that we should be talking about liquidity, not money; that the the link between any quantifiable money stock and real activity had broken down by the early 1980s if not before (my point was only that it wasn't entirely obvious until the great financial crisis); that to make sense of this stuff you need a concrete, institutionally grounded account of the financial system; and that for that, a very good place to start is Perry Mehrling's work.)
Some cavils:

The meaningfulness of monetary aggregates depends on the configuration of the credit system. In a world of tight banking regulations, the monetarist assumption that "there's a stable relationship between outside money and inside money" worked fine precisely because regulations made it so. Once those regulations break down, the relationship between outside and and inside money transforms. As the mainstream understands, "the rapid pace of financial innovation in the United States has been an important reason for the instability of the relationships between monetary aggregates and other macroeconomic variables" (Bernanke, "Monetary Aggregates and Monetary Policy at the Federal Reserve: A Historical Perspective," FRB 2006).

Thus your claim that "Between 1990 and 2008, this [monetarist] story isn't glaringly incompatible with the evidence" is not entirely true. Post-deregulation, money demand ("velocity") became quite unmeasurable, breaking the link between the two sides of the quantity equation. "Behavior" had already changed significantly by the late 1960s, i.e. just as the monetarists were gaining the upper hand in the battle of ideas. (Note that the Fed eventually stopped measuring M3; but not everyone did: http://www.shadowstats.com/charts/monetary-base-money-supply).

Eventually, in response to this breakdown, the Fed quits its ill-conceived monetarist experiment and targets price rather quantity, specifically the Fed Funds rate. Thus "changing the stock of base money" has not been "the instrument of central banks, at least in theory, since the early 20th century." Since the empirical and theoretical tractability of "the money supply" gave way, monetary control moved to the price of central-bank refinance, i.e. "the price of liquidity." [1]

Price-based control works by acting on the leverage capacity of the balance sheets "downstream," most immediately those in the primary dealer system. (Mehrling, New Lombard Street). Modulation of this capacity is effected through changes in the price of refinance---the bailout price---for these dealers, thereby changing their bid-ask spread. So changes in the prices of the assets in which they make markets are a key transmission mechanism to changes in interest rates.

The effect interest rates have on investment and/or consumer demand itself depends on the configuration of the credit system, i.e. how investment and consumption are financed. The price of credit might not be as important as its quantity for investment, but the former might be very important for consumption and thus aggregate demand.
So you can get a recession thanks to insufficient aggregate demand if you have a credit system that ties consumption to finance. The reason is the same as that which enables what Mehrling calls "monetary policy without sticky prices," i.e. the leverage capacity of (in this case, consuming) balance sheets. If people are stuffed with debt, their "excess demand for money" basically represents a demand for liquidity to pay down their debts. Extra income will go first and foremost towards deleveraging rather than consumption; this of course is Richard Koo's Minsky-flavored lesson from Japan.

Given the current configuration of the system, a coordination problem of the kind referred to would mean that those with spare lending capacity can't find those with spare borrowing capacity. Yet in sectoral terms, its only households that are truly overleveraged: government is only political so and business are relatively okay. The problem is to get the big balance sheet with the spare capacity online again; of course, that is a political problem.[2] Boosting liquidity qua "the money supply" will simply pass through to paying down debts before it starts to affect consumption and thereby investment. In short, we might be some time, especially if we abstract away from the institutional configuration of the credit system.

[1] This signaled a return to pre-WWI "banking school" methods employed by the Bank of England, modulo differences in the respective credit systems: commercial paper for the trade-credit-based English system and government paper for the postwar US system. The Fed in our own period seems to be feeling its way to dealing in paper other than the government's (QE I), something that is appropriate given the importance of non-government debt in the present system.

[2] Incidentally, Morris Copeland's analogy of the credit system as an electric grid works much better than Fisher's "currency school" vision of money as a liquid. See http://www.nber.org/books/cope52-1.

Friday, September 16, 2011

What's the Matter with (Quasi-)Monetarism?

Let's start from the top.

What is monetarism? As I see it, it's a set of three claims. (1) There is a stable relationship between base money and the economically-relevant stock of money. [1] That is, there's a stable relationship between outside money and inside money. (2) There is a stable velocity of money, so we can interpret the equation of exchange MV = PY (or MV = PT) as a behavioral relationship and not just an accounting identity. Since the first claim says that M is set exogenously by the monetary authority, causality in the equation runs from left to right. And (3), the LM aggregate supply curve is shaped like a backward L, so that changes in PY show up entire in Y when the economy is below capacity, and entirely in changes in P when it is at capacity.

In other words, (1) the central bank can control the supply of money; (2) the supply of money determines the level of nominal output; and (3) there is a single strictly optimal level of nominal output, without any tradeoffs. The implication is that monetary policy should be guided by a simple rule, that the money supply should grow at a fixed rate equal to (what we think is) the growth rate of potential output. Which is indeed, exactly what Friedman and other monetarists said.

You can relax (3) if you want -- most monetarists would probably agree that in practice, disinflation is going to involve a period of depressed output. (Altho on the other hand, I'm pretty sure that when monetarism was officially adopted as the doctrine of the bank of England under Thatcher, it was claimed that slowing the growth of the money supply would control inflation without affecting growth at all. And the hedge-monetarism you run into today, that insists the huge growth in base money over the past few years could show up as hyperinflation without warning, seems to be implicitly assuming a backward-L shaped LM AS curve as well.) But basically, that's the monetarist package.

So what's wrong with this story? Here's what:

The red line is base money, the blue line is broad money (M2), and the green line is nominal GDP. The monetarist story is that red moves blue, and blue moves green. Between 1990 and 2008, this story isn't glaringly incompatible with the evidence. But since then? It's clear that the money multiplier, as we normally talk about it, no longer has any economic reality. There might still be tools out there to control the money supply. But changing the stock of base money -- the instrument of central banks, at least in theory, since the early 20th century -- is no longer one of them. Monetary policy as we knew it is dead. The divergence between the blue and green lines is less dramatic in this graph, but if anything it's even more damning. While output and prices lurched downward in the great Recession, the money supply just kept chugging along. Milton Friedman's idea that stable growth of the money supply is a sufficient condition for stable growth of nominal GDP looks pretty definitively refuted.

So that's monetarism, and what's the matter with it. How about quasi-monetarism? What's the difference from the unprefixed kind?

Some people would say, There is no difference. Quasi-monetarist is just what we call a New Keynesian who's taken off his Keynes mask and admitted he was a Friedmanite all along. And let's be honest, that's sort of true. But it's like one of those episodes in religious history where at some point the disciples have to acknowledge that, ok, the prophecies don't seem to have exactly worked out. Which means we have to figure out what they really meant.

In this case, the core commitment is the idea that if PY is too low (we're experiencing a recession and/or deflation) that means M is too low; if PY is too high (we're experiencing inflation) that means M is too high. In other words, when we talk about insufficient aggregate demand, what we're really talking about is just excess demand for money. And therefore, when we talk about policies to boost demand, we're really just talking about policies to boost the money stock. (Nick Rowe, as usual, is admirably straightforward on this point.) But how to reconcile this with the graph above? You just have to replace some material entities with spiritual ones: The true M, or V, or both, is not visible to mortal eyes. Let's say that velocity is exogenous but not stable. Then there is still a unique path of M that would guarantee both full employment and stable prices, but it can't be characterized as a simple growth rate as Friedman hoped. Alternatively, maybe the problem is that the monetary authority can only control M clumsily, and can't directly observe how far off it is. (This is the DeLong version of quasi-monetarism. The assets that count as M are always changing.) Then, there may still be the One True Growth Rate of M just as Friedman promised, but the monetary authority can't reliably implement it. Or sublunary M and V could both depart from their platonic ideals. In any case, the answer is clear: Since it's hard to get MV right, your rule should be to target a steady growth rate of PY (nominal GDP). Which is, indeed, exactly what the quasi-monetarists say. [2]

So what's the alternative? I've been arguing that one alternative is to think of recessions as coordination failures, which could happen even in an economy without money. I'm honestly not sure if that's going to turn out to be a productive direction to go in, or not. But in terms of the monetarist framework, the alternative is clear. Say that V is not only unstable, but endogenous. Specifically, say that it varies inversely with M. In this case, it remains true -- as it must; it's an accounting identity -- that MV = PY. But nonetheless there is nothing you can do to M, that will affect P or Y. (This situation, by the way, is what Keynes meant by a liquidity trap. It wasn't about the zero lower bound.)

This, I think, is what we actually observe, not just right now, but in general. "The" interest rate is the price of liquidity, that is, the price of money. [3] And what kinds of activity are sensitive to interest rates? Well, uh ... none of them. None, anyway, except for housing. When an economic unit is deciding on the division of its income between currently-produced goods and services vs. money, the price at which they exchange just doesn't seem to be much of a consideration. (Again, except -- and it's an important exception -- when the decision takes the form of purchasing housing services from either an existing home, or a new one.) Which means that changes in M don't have any good channel to produce changes in P or Y. In general, increases or decreases in M will just result in pro rata decreases or increases in V. Yes, it may be formally true that insufficient demand for goods equals excess demand for money; but it doesn't matter if there's no well-defined money demand function. A traditional Keynesian expenditure function (Z = A + cY) cannot be usefully simplified, as the quasi-monetarists would like, by thinking of it as a problem of maximizing the flow of consumption subject to some real balance constraint.

So, monetarism made some strong predictions. Quasi-monetarism admits that those predictions don't hold up, but argues that the monetarist model is still the right one, we just can't observe the variables in it as directly as early monetarists hoped. On some level, they may be right! But at some point, when the model gets too loosely coupled with reality, you'll want to stop using it. Even if, in some sense, it isn't wrong.

Which is all to say that, even if I can't find a way to disprove it analytically, I just can't accept the idea that the question of aggregate demand can be usefully reduced to the question of the supply of money.

[1] The simplest form of the first claim would be that the money multiplier is equal to one: Outside money is all the money there is. Something like this was supposed to be true under the gold standard, tho as the great Robert Triffin points out, it wasn't really. Over at Windyanabasis, rsj claims that Krugman, a closet quasi-monetarist, implicitly makes this assumption.

[2] In practice, despite the tone of this post, I'm not entirely sure they're wrong. More generally, Nick Rowe's clear and thorough posts on this set of questions are essential reading.

[3] I've learned from  Bob Pollin never to write that phrase without the quotes. There are lots of interest rates, and it matters.

Tuesday, September 13, 2011

Are Recessions All About Money: Quasi-Monetarists and Babysitting Co-ops

Today Paul Krugman takes up the question of the post below, are recessions all about (excess demand for) money? The post is in response to an interesting criticism by Henry Kaspar of what Kaspar calls "quasi-monetarists," a useful term. Let me rephrase Kaspar's summary of the quasi-monetarist position [1]:

1. Logically, insufficient demand for goods implies excess demand for money, and vice versa.
2. Causally, excess demand for money (i.e. an increase in liquidity preference or a fall in the money supply) is what leads to insufficient demand for goods.
3. The solution is for the monetary authority to increase the supply of money.

Quasi-monetarists say that 2 is true and 3 follows from it. Kaspar says that 2 doesn't imply 3, and anyway both are false. And Krugman says that 3 is false because of the zero lower bound, and it doesn't matter if 2 is true, since asking for "the" cause of the crisis is a fool's errand. But everyone agrees on 1.

Me, though, I have doubts.

An overall shortfall of demand, in which people just don’t want to buy enough goods to maintain full employment, can only happen in a monetary economy; it’s correct to say that what’s happening in such a situation is that people are trying to hoard money instead (which is the moral of the story of the baby-sitting coop). And this problem can ordinarily be solved by simply providing more money.
For those who don't know it, Krugman's baby-sitting co-op story is about a group that let members "sell" baby-sitting services to each other in return for tokens, which they could redeem later when they needed baby-sitting themselves. The problem was, too many people wanted to save up tokens, meaning nobody would use them to buy baby-sitting and the system was falling apart. Then someone realizes the answer is to increase the number of tokens, and the whole system runs smoothly again. It's a great story, one of the rare cases where Keynesian conclusions can be drawn by analogizing the macroeconomy to everyday experience. But I'm not convinced that the fact that demand constraints can arise from money-hoarding, means that they always necessarily do.

Let's think of the baby-sitting co-op again, but now as a barter economy. Every baby-sitting contract involves two households [2] committing to baby-sit for each other (on different nights, obviously). Unlike in Krugman's case, there's no scrip; the only way to consume baby-sitting services is to simultaneously agree to produce them at a given date. Can there be a problem of aggregate demand in this barter economy. Krugman says no; there are plenty of passages where Keynes seems to say no too. But I say, sure, why not?

Let's assume that participants in the co-op decide each period whether or not to submit an offer, consisting of the nights they'd like to go out and the nights they're available to baby-sit. Whether or not a transaction takes place depends, of course, on whether some other participant has submitted an offer with corresponding nights to baby-sit and go out. Let's call the expected probability of an offer succeeding p. However, there's a cost to submitting an offer: because it takes time, because it's inconvenient, or just because, as Janet Malcolm says, it isn't pleasant for a grown man or woman to ask for something when there's a possibility of being refused. Call the cost c. And, the net benefit from fulfilling a contract -- that is, the enjoyment of going out baby-free less the annoyance of a night babysitting -- we'll call U.

So someone will make an offer only when U > c/p. (If say, there is a fifty-fifty chance that an offer will result in a deal, then the benefit from a contract must be at least twice the cost of an offer, since on average you will make two offers for eve contract.) But the problem is, p depends on the behavior of other participants. The more people who are making offers, the greater the chance that any given offer will encounter a matching one and a deal will take place.

It's easy to show that this system can have multiple, demand-determined equilibria, even though it is a pure barter economy. Let's call p* the true probability of an offer succeeding; p* isn't known to the participants, who instead form p by some kind of backward-looking expectations looking at the proportion of their own offers that have succeeded or failed recently. Let's assume for simplicity that p* is simply equal to the proportion of participants who make offers in any given week. Let's set c = 2. And let's say that every week, participants are interested in a sitter one night. In half those weeks, they really want it (U = 6) and in the other half, they'd kind of like it (U = 3). If everybody makes offers only when they really need a sitter, then p = 0.5, meaning half the contracts are fulfilled, giving an expected utility per offer of 2. Since the expected utility from making an offer on a night you only kind of want a sitter is - 1, nobody tries to make offers for those nights, and the equilibrium is stable. On the other hand, if people make offers on both the must-go-out and could-go-out nights, then p = 1, so all the offers have positive expected utility. That equilibrium is stable too. In the first equilibrium, total output is 1 util per participant per week, in the second it's 2.5.

Now suppose you are stuck in the low equilibrium. How can you get to the high one? Not by increasing the supply of money -- there's no money in the system. And not by changing prices -- the price of a night of baby-sitting, in units of nights of baby-sitting, can't be anything but one. But suppose half the population decided they really wanted to go out every week. Now p* rises to 3/4, and over time, as people observe more of their offers succeeding, p rises toward 3/4 as well. And once p crosses 2/3, offers on the kind-of-want-to-go-out nights have positive expected utility, so people start making offers for those nights as well, so p* rises further, toward one. At that point, even if the underlying demand functions go back to their original form, with a must-go-out night only every other week, the new high-output equilibrium will be stable.

As with any model, of course, the formal properties are less interesting in themselves than for what they illuminate in the real world. Is the Krugman token-shortage model or my pure coordination failure model a better heuristic for understanding recessions in the real world? That's a hard question!

Hopefully I'll offer some arguments on that question soon. But I do want to make one logical point first, the same as in the last post but perhaps clearer now. The statement "if there is insufficient demand for currently produced goods, there must excess be demand for money" may look quite similar to the statement "if current output is limited by demand, there must be excess demand for money." But they're really quite different; and while the first must be true in some sense, the second, as my hypothetical babysitting co-op shows, is not true at all. As Bruce Wilder suggests in comments, the first version is relevant to acute crises, while the second may be more relevant to prolonged periods of depressed output. But I don't think either Krugman, Kaspar or the quasi-monetarists make the distinction clearly.

EDIT: Thanks to anonymous commenter for a couple typo corrections, one of them important. Crowd-sourced editing is the best.

Also, you could think of my babysitting example as similar to a Keynesian Cross, which we normally think of as the accounting identity that expenditure equals output, Z = Y, plus the behavioral equation for expenditure, Z = A + cY, except here with A = 0 and c = 1. In that case any level of output is an equilibrium. This is quasi-monetarist Nick Rowe's idea, but he seems to be OK with my interpretation of it.

FURTHER EDIT: Nick Rowe has a very thoughtful response here. And my new favorite econ blogger, the mysterious rsj, has a very good discussion of these same questions here. Hopefully there'll be some responses here to both, soonish.

[1] Something about typing this sentence reminds me unavoidably of Lucky Jim. This what neglected topic? This strangely what topic? Summary of the quasi-what?

[2] Can't help being bugged a little by the way Krugman always refers to the participants as "couples," even if they mostly were. There are all kinds of families!