Global Imbalances

I gave some comments on “Global Imbalances and Currency Wars at the ZLB,” by Ricardo J. Caballero, Emmanuel Farhi, and Pierre-Olivier Gourinchas at the conference, “International Monetary Stability: Past, Present and Future”, Hoover Institution, May 5 2016. My comments are here, the paper is here 

The paper is a very clever and detailed model of "Global Imbalances," "Safe asset shortages" and the zero bound. A country's inability to "produce safe assets" spills, at the zero bound, across to output fluctuations around the world. I disagree with just about everything, and outline an alternative world view.

A quick overview:

Why are interest rates so low? Pierre-Olivier & Co.: countries can't  “produce safe stores of value”
This is entirely a financial friction. Real investment opportunities are unchanged. Economies can’t “produce” enough pieces of paper. Me: Productivity is low, so marginal product of capital is low.

Why is growth so low? Pierre-Olivier: The Zero Lower Bound is a "tipping point." Above the ZLB, things are fine. Below ZLB, the extra saving from above drives output gaps. It's all gaps, demand. Me: Productivity is low, interest rates are low, so output and output growth are low.

Data: I Don't see a big change in dynamics at and before the ZLB. If anything, things are more stable now that central banks are stuck at zero. Too slow, but stable.  Gaps and unemployment are down. It's not "demand" anymore.


Exchange rates. Pierre-Olivier  "indeterminacy when at the ZLB” induces extra volatility. Central banks can try to "coordinate expectations." Me: FTPL gives determinacy, but volatility in exchange rates. There is no big difference at the ZLB.

Safe asset Shortages. Pierre-Olivier: driven by a large mass of infinitely risk averse agents. Risk premia are therefore just as high as in the crisis. Me: Risk premia seem low. And doesn't everyone complain about "reach for yield" and low risk premia?

Observation. These ingredients are plausible about fall 2008. But that's nearly 8 years ago! At some point we have to get past financial crisis theory to not-enough-growth theory.

But, finally, praise. This is a great paper. It clearly articulates a world view, and you can look at the assumptions and mechanisms and decide if you think they make sense. I am in awe that Pierre-Olivier & Co. were able to make a coherent model of these buzzwords.

But great theory is great theory. To a critic, the assumptions are necessary as well as sufficient. I  read it as a brilliant negative paper, almost a parody: Here are the extreme assumptions that it takes to justify all the policy blather about "savings gluts" "global imbalances" "safe asset shortages" and so on. To me, it shows just how empty the idea is, that our policy-makers understand any of this stuff at a scientific, empirically-tested level, and should take strong actions to offset the supposed problems these buzzwords allude to.

I hope this taste gets you to read  my comments and the paper. 

Macro Musing Podcast

I did a podcast with David Beckworth, in his "macro musings" series, on the Fiscal Theory of the Price Level, blogging, and a few other things.



(you should see the link above, if not click here to return to the original).

You can also get the podcast at Sound Cloud, along with all the other ones he has done so far, or on itunes here.  For more information, see David's post on the podcast.

A very simple neo-Fisherian model

A sharp colleague recently pushed me to write down a really simple model that can clarify the intuition of how raising interest rates might raise, rather than lower, inflation. Here is an answer.

(This follows the last post on the question, which links to a paper. Warning: this post uses mathjax and has graphs. If you don't see them, come back to the original. I have to hit shift-reload twice to see math in Safari. )

I'll use the standard intertemporal-substitution relation, that higher real interest rates induce you to postpone consumption, \[ c_t = E_t c_{t+1} - \sigma(i_t - E_t \pi_{t+1}) \] I'll pair it here with the simplest possible Phillips curve, that inflation is higher when output is higher. \[ \pi_t = \kappa c_t \] I'll also assume that people know about the interest rate rise ahead of time, so \(\pi_{t+1}=E_t\pi_{t+1}\).

Now substitute \(\pi_t\) for \(c_t\), \[ \pi_t = \pi_{t+1} - \sigma \kappa(i_t - \pi_{t+1})\] So the solution is \[ E_t \pi_{t+1} = \frac{1}{1+\sigma\kappa} \pi_t + \frac{\sigma \kappa}{1+\sigma\kappa}i_t \]

Inflation is stable. You can solve this backwards to \[ \pi_{t} = \frac{\sigma \kappa}{1+\sigma\kappa} \sum_{j=0}^\infty \left( \frac{1}{1+\sigma\kappa}\right)^j i_{t-j} \]

Here is a plot of what happens when the Fed raises nominal interest rates, using \(\sigma=1, \kappa=1\):

When interest rates rise, inflation rises steadily.

Now, intuition. (In economics intuition describes equations. If you have intuition but can't quite come up with the equations, you have a hunch not a result.) During the time of high real interest rates -- when the nominal rate has risen, but inflation has not yet caught up -- consumption must grow faster.

People consume less ahead of the time of high real interest rates, so they have more savings, and earn more interest on those savings. Afterwards, they can consume more. Since more consumption pushes up prices, giving more inflation, inflation must also rise during the period of high consumption growth.

One way to look at this is that consumption and inflation was depressed before the rise, because people knew the rise was going to happen. In that sense, higher interest rates do lower consumption, but rational expectations reverses the arrow of time: higher future interest rates lower consumption and inflation today.

(The case of a surprise rise in interest rates is a bit more subtle. It's possible in that case that \(\pi_t\) and \(c_t\) jump down unexpectedly at time \(t\) when \(i_t\) jumps up. Analyzing that case, like all the other complications, takes a paper not a blog post. The point here was to show a simple model that illustrates the possibility of a neo-Fisherian result, not to argue that the result is general. My skeptical colleauge wanted to see how it's even possible.)

I really like that the Phillips curve here is so completely old fashioned. This is Phillips' Phillips curve, with a permanent inflation-output tradeoff. That fact shows squarely where the neo-Fisherian result comes from. The forward-looking intertemporal-substitution IS equation is the central ingredient.

Model 2:

You might object that with this static Phillips curve, there is a permanent inflation-output tradeoff. Maybe we're getting the permanent rise in inflation from the permanent rise in output? No, but let's see it. Here's the same model with an accelerationist Phillips curve, with slowly adaptive expectations. Change the Phillips curve to \[ c_{t} = \kappa(\pi_{t}-\pi_{t-1}^{e}) \] \[ \pi_{t}^{e} = \lambda\pi_{t-1}^{e}+(1-\lambda)\pi_{t} \] or, equivalently, \[ \pi_{t}^{e}=(1-\lambda)\sum_{j=0}^{\infty}\lambda^{j}\pi_{t-j}. \]

Substituting out consumption again, \[ (\pi_{t}-\pi_{t-1}^{e})=(\pi_{t+1}-\pi_{t}^{e})-\sigma\kappa(i_{t}-\pi_{t+1}) \] \[ (1+\sigma\kappa)\pi_{t+1}=\pi_{t}+\pi_{t}^{e}-\pi_{t-1}^{e}+\sigma\kappa i_{t} \] \[ \pi_{t+1}=\frac{1}{1+\sigma\kappa}\left( \pi_{t}+\pi_{t}^{e}-\pi_{t-1} ^{e}\right) +\frac{\sigma\kappa}{1+\sigma\kappa}i_{t}. \] Explicitly, \[ (1+\sigma\kappa)\pi_{t+1}=\pi_{t}+\gamma(1-\lambda)\left[ \sum_{j=0}^{\infty }\lambda^{j}\Delta\pi_{t-j}\right] +\sigma\kappa i_{t} \]

Simulating this model, with \(\lambda=0.9\).

As you can see, we still have a completely positive response. Inflation ends up moving one for one with the rate change. Consumption booms and then slowly reverts to zero. The words are really about the same.

The positive consumption response does not survive with more realistic or better grounded Phillips curves. With the standard forward looking new Keynesian Phillips curve inflation looks about the same, but output goes down throughout the episode: you get stagflation.

The absolutely simplest model is, of course, just \[i_t = r + E_t \pi_{t+1}\]. Then if the Fed raises
the nominal interest rate, inflation must follow. But my challenge was to spell out the market forces
that push inflation up. I'm less able to tell the corresponding story in very simple terms.

Deflation Puzzle

Larry Summers writes an eloquent FT column "A world stumped by stubbornly low inflation"

Market measures of inflation expectations have been collapsing and on the Fed’s preferred inflation measure are now in the range of 1-1.25 per cent over the next decade.

Inflation expectations are even lower in Europe and Japan. Survey measures have shown sharp declines in recent months. Commodity prices are at multi-decade lows and the dollar has only risen as rapidly as in the past 18 months twice during the past 40 years when it has fluctuated widely

And the Fed is forecasting a return to its 2 per cent inflation target on the basis of models that are not convincing to most outside observers. 

Central bankers [at the G20 meeting] communicated a sense that there was relatively little left that they can do to strengthen growth or even to raise inflation. This message was reinforced by the highly negative market reaction to Japan’s move to negative interest rates.

So why is inflation slowly declining despite our central banks' best efforts? Here is a stab at an answer. I emphasize the central logical points with bullets.

• Interest rates have two effects on inflation: a short-run "liquidity" effect, and a long-run "expected inflation" or "Fisher" effect.  

In normal times, to raise interest rates, the central bank sells bonds, which soaks up money. Less money drives up interest rates as people bid to borrow a smaller supply, and less money also reduces "demand," which reduces inflation.  In the long run, higher inflation and higher interest rates go together, as they did in the 1980s.

However, we are now in a classic "liquidity trap." Interest rates have been zero since 2008. Money and bonds are perfect substitutes. The proof of that is in the pudding: the Fed massively increased excess reserves from less than $50 billion to almost $3,000 billion, and inflation keeps trundling down.

• In a liquidity trap, the liquidity effect is absent. 

The liquidity effect will remain absent as the Fed starts raising interest rates, and would remain absent if the Fed were to cut rates or reduce them below zero as other central banks are doing. You can't have more than perfect liquidity.

The Fed isn't even planning to try. It plans to keep the $3,000 billion of excess reserves outstanding and raise interest rates by raising the interest rate on reserves. There will be no open market operations, no "tightening" associated with this interest rate raise.  But even if it did, we're $2,950 billion of excess reserves away from any liquidity effect, so it wouldn't matter.

• When the liquidity effect is absent, the expected inflation effect is all that remains. Inflation must follow interest rates. 

Central banks thought they were raising inflation by lowering interest rates, following experience from the normal-times liquidity-effect correlation between lower interest rates and higher inflation. But that experience does not apply when its liquidity effect is turned off.

With no liquidity effect, lowering interest rates further below zero can only, slowly, lower inflation further. Central banks desiring inflation may have followed a classic pedal mis-application.

Do I "believe" this story? Belief has no place in science. It is the simplest coherent story that explains the last few years, not needing lots of frictions, irrationalities, and other assumptions. I have some equations to back it up. But we don't "believe" anything at least until it's published and has survived critical examination, replication and dissection. Still, I think it merits consideration.

Shh. I like zero inflation. If central banks have the wrong pedal but are driving the right speed anyway, why wake them up? Even Larry seems to have given up on the Phillips curve:

...suppose that officials were comfortable with current policy settings based on the argument that Phillips curve models predicted that inflation would revert over time to target due to the supposed relationship between unemployment and price increases.

There is no sign of the dreaded "deflation vortex," any more than there is any sign of dreaded monetary hyperinflation. We're drifting down to the Friedman rule. As Larry emphasizes, don't get excited over forecasts from models that rather spectacularly did not forecast where we are today. 
Central banks' desire for 2% inflation, and the Fed's rather puzzling interpretation of its "price stability" mandate to mean perpetual 2% inflation may also be relics of the bygone liquidity-effect regime. 

Appreciate the first half of the column which turns the signs around. It's a great bit of rhetoric.

I have to register mild disagreement with Larry's "solution" to the supposed "problem," 

In all likelihood the important elements will be a combination of fiscal expansion drawing on the opportunity created by super low rates and, in extremis, further experimentation with unconventional monetary policies.

He doesn't say which monetary policies would work, given they have not done so yet. But these are topics for another day.

(Note: If quote and bullet formatting doesn't show up, come back to the original.)

Negative rates and FTPL

I've devoted most of my monetary economics research agenda to the Fiscal Theory of the Price Level in the last two decades (collection here). This theory says, fundamentally, that money has value because the government accepts it for taxes, and inflation is fundamentally a fiscal phenomenon over which central banks' conventional tools -- open market operations trading money for government bonds -- have limited power.

Since I grew up in the 1970s, I figured the FTPL would have its day when inflation unexpectedly broke out, again, and central banks were powerless to stop it. I figured that the spread of interest-paying electronic money would so clearly undermine the foundations of MV=PY that its pleasant stories would be quickly abandoned as no longer relevant.

I may have been  exactly wrong on both points: It seems that uncontrolled disinflation or deflation will be the spark for adoption of FTPL ideas; that the equivalence of money and bonds at zero interest rates,  and central banks powerless to create inflation will be the trigger.

These thoughts are prodded by two pieces in the Economist, "Out of Ammo:" and "Unfamiliar Ways Forward" (HT and interesting discussion by Miles Kimball)

If you want inflation (a big if -- I don't, but let's go with the if) how do you get it? Ultra-low rates, huge bond purchases, and lots of talk (forward guidance, higher inflation targets) seem to have no effect. What can governments actually do?


"Out of ammo" explains

... At least some of them [politicians] have failed to grasp the need to have fiscal and monetary policy operating in concert....

... One such option is to finance public spending (or tax cuts) directly by printing money—known as a “helicopter drop”. Unlike QE, a helicopter drop bypasses banks and financial markets, and puts freshly printed cash straight into people’s pockets. The sheer recklessness of this would, in theory, encourage people to spend the windfall, not save it. 

The "recklessness" part is crucial. "Unfamiliar ways" has a more intricate scheme to communicate that recklessness

..a central bank and its finance ministry ... collude in printing money to pay for public spending (or tax cuts). ...the government announces a tax rebate and issues bonds to finance it, but instead of selling them to private investors swaps them for a deposit with the central bank. The central bank proceeds to cancel the bonds, and the government withdraws the money it has on deposit and gives it to citizens. “Helicopter money” of this sort—named in honour of a parable told by Milton Friedman, a famous economist—is as close as you can get to raining cash from a clear blue sky like manna from heaven, untouched by banks and financial markets.

Such largesse is, in effect, fiscal policy financed by money instead of bonds... But the unaccustomed drama—indeed, the apparent recklessness—of helicopter money could increase the expected inflation rate, encouraging taxpayers to spend rather than save.

Simpler, in my mind, the Treasury borrows and sends checks to voters. The Fed buys the bonds and then cancels them.

In addition to rather convoluted scheme, the pieces are not quite clear why the fiscal counterpart is necessary -- or why money has to be involved with fiscal policy.  That was not a central part of Friedman's helicopters. Miles is clearer about this:

the government give[s] away so much money that people would be convinced there was no way the government could ever sell enough bonds to soak that money up. 

This is clear and good FTPL thinking. The value of money is set by how much there is vs how much people expect the government to soak up via taxes -- or bond sales, backed by credible promises of future taxes.

If the government drops $100 in every voter's pocket but simultaneously announces "austerity" that taxes are going up $100 tomorrow, even helicopter drops would have no effect.

Helicopter drops are a clever fiscal signaling device. Canceling the bonds in the Economists plan is the crucial signaling device. They say "we are really going to be reckless."  When governments sell a lot of bonds, people think  the government is sooner or later going to soak up these bonds with taxes, and do not spend. That's the whole point -- bond sales are set up to raise revenue, not to create inflation.  The whole canceling the bonds thing in the Economists's plan, or the helicopter drama in Friedman's, is a clever psychological device, to convince people that no, the government is not going to raise taxes to soak money or underlying bonds up, so you'd better spend it now before it loses value.

Well if (if) our central banks want inflation, why not get out the helicopters?

Such shenanigans are not possible in the euro zone, where the ECB is forbidden by treaty from buying government bonds directly. Elsewhere they might work as follows: 

monetary financing is prohibited by the treaties underpinning the euro, for example

The US Federal reserve is similarly constrained to always buy something in return for creating money -- it can't send checks to voters.

Why?  The people who set up our monetary systems understood all this very well. Their memories were full of disastrous inflations, and they understood that printing money without clear promises that taxes would eventually soak up that money would lead quickly to inflation. So, yes, central banks are prohibited from doing the one thing that would most quickly produce inflation! For about the same reason that wise parents don't keep the car keys in the liquor cabinet.  (There are also all sorts of good political economy reasons that an independent central bank should not lend to specific businesses or send checks to voters.)

The Economist articles are also quite good at the evidence that current monetary policy is essentially powerless.

If policymakers appear defenceless in the face of a fresh threat to the world economy, it is in part because they have so little to show for their past efforts. The balance-sheets of the rich world’s main central banks have been pumped up to between 20% and 25% of GDP by the successive bouts of QE with which they have injected money into their economies (see chart 1). The Bank of Japan’s assets are a whopping 77% of GDP. Yet inflation has been persistently below the 2% goal that central banks aim for.

The power of open market operations -- buying bonds in return for money - is just dramatically refuted, at least at zero interest rates, by recent experience.

One way to get them back up might be to set a higher inflation target. But when inflation sits so persistently below today’s targets, persuading people that higher targets would produce higher rates will require action, not just words.

Or as I call it, the speak loudly because you have no stick policy. If central banks announce a 5% inflation target, and inflation goes down anyway, now what? Announce a 10% target?

Miles goes on about the power of negative interest rates to stoke inflation, which will be a topic for another day. If negative 2% real rates (2% inflation, 0% interest) didn't stoke "demand" and revive the extinct Phillips curve,  I don't see how negative 3% (2% inflation  -1% interest rate) or negative 5% will finally do the trick. In the standard models I've been playing with,  raising nominal interest rates, and committing to keep them there, is the way for central banks to raise expected inflation. That action would, however, also cool the economy, producing stagflation, and thus be particularly pointless.

I also fully admit that I'm cherry-picking the things I like from the Economist article, and ignoring all sorts of things that seem pretty silly to me. The point: I'm glad to see fiscal-theory thinking making its way out of academic debate into real-world commentary, if only in the "radical ideas" section.  Now, on to the "conventional wisdom" section!