Raise interest rates to raise inflation? Lower interest rates to lower inflation? It's not that simple.
A correspondent from an emerging market wrote enthusiastically. His country has somewhat too high inflation, currency depreciation and slightly negative real rates. A discussion is going on about raising rates to combat inflation. Do I think that lowering rates in this circumstance is instead the way to go about it?
As you can tell, posing the question this way makes me very uncomfortable! So, thinking out loud, why might one pause at jumping this far, this fast?
Fiscal policy. Fiscal policy deeply underlies monetary policy. In my own "Fisherian" explorations, the fiscal theory of price level is a deep foundation. If the government is printing up money to pay its bills, the central bank can do what it wants with interest rates, inflation is coming anyway.
Conversely, underlying the decline in inflation in the US, Europe, and Japan is an extraordinary demand for nominal government debt.
Bond markets seem to think we'll pay it off. And that is not too terribly an irrational expectation. Sovereign debts are self-inflicted wounds. A little structural reform to get growing again, tweaks to social security and medicare, and next thing you know we're back in the 1990s and wondering what to do when all the government bonds are paid off. Also, valuation is more about discount rates than cashflows. People seem happy - for now - to hold government debt despite unusually low prospective returns.
My correspondent answers that his country is actually doing well fiscally. However, his country is also a bit low on reserves and having exchange rate and capital flight problems.
But current deficits are not that important to inflation either in theory or in fact. The fiscal policy that matters is expectations of very long term stability, not just a few years of surpluses. Also, contingent liabilities matter a lot. If investors in government debt see a government that will bail out all and sundry in the next downturn, or faces political risks, even temporary surpluses are not an assurance to investors. (Craig Burnside, Marty Eichenbaum and Sergio Rebelo's "Prospective Deficits and the Asian Currency Crises, in the JPE and ungated here is a brilliant paper on this point.)
Rational expectations. The Fisherian proposition also relies deeply on rational expectations. In the simplest version, it=r+Etπt+1it=r+Etπt+1, people see nominal interest rates rise, they expect inflation to be higher, so they raise their prices. As a result of that expectation inflation is, on average, higher. (Loose story alert.)
How do they expect such a thing? Well, rational expectations is sensible when there is a long history in one regime. People see higher interest rates, they remember times of high interest rates in the past, like the late 1970s, so they ratchet up their inflation expectations. Or, people see higher interest rates, and they've gotten used to the Fed raising interest rates when the Fed sees inflation coming, so they raise their expectations. The motto of rational expectations is "you can't fool all of the people all of the time," not "you can never fool anyone," nor "people are clairvoyant."
The Fisherian prediction relies on the interest rate change to be credible, long-lasting, and to lead to the right expectations. A one-off experiment, that might be read as cover for a dovish desire to boost growth at the expense of more inflation, and that might be quickly reversed doesn't really map to the equations. Europe and Japan, stuck at the zero bound, with a fiscal bonanza (low interest costs on the debt) and slowly decreasing inflation expectations is much more consistent with those equations.
Liquidity. When interest rates are positive and money does not pay interest, lowering rates means more money in the system, and potentially more lending too. This classic liquidity channel, which goes the other way, is absent for the US, UK, Japan and Europe, since we're at the zero bound and since reserves pay interest. (Granted, I couldn't get the equations of the liquidity effect to be large enough to offset the Fisher effect, but that depends on the particulars of a model.)
Successful disinflations. Disinflations are a combination of fiscal policy, monetary policy, expectations, and liquidity. Tom Sargent's classic ends of four hyperinflations tells the story beautifully.
Large inflations result from intractable fiscal problems, not central bank stupidity. In Tom's examples, the government solves the fiscal problem; not just immediately, but credibly solves it for the foreseeable future. For example, the German government in the 1920s faced enormous reparations payments. Renegotiating these payments fixed the underlying fiscal problem. When the long-term fiscal problem was fixed, inflation stopped immediately. Since everybody knew what the fiscal problem was, expectations were quickly rational.
The end of inflation coincided with a large money expansion and a steep reduction in nominal interest rates. During a time of high inflation, people use as little money as possible. With inflation over, real money demand expands. There was no period of monetary stringency or interest-rate raising preceding these disinflations.
So these are great examples in which the Fisher story works well - lower interest rates correspond to lower inflation, immediately. But you can see that lower interest rates are not the whole story. The central bank of Germany 1922 could not have stopped inflation on its own by lowering rates. I suspect the same is true of high inflation countries today - usually something is wrong other than just the history of interest rates.
So, apply new theories with caution!
To the raising interest rates question for the US and Europe, some of the same considerations apply. We won't have any liquidity effects, as central banks are planning to just pay more interest on abundant reserves. Higher real interest rates will raise fiscal interest costs, which is an inflationary shock by fiscal theory considerations. The big question is expectations. Will people read higher interest rates as a warning of inflation about to break out, or as a sign that inflation will be even lower?