最後の貸し手機能とインフレーション・ターゲティング

●Robert E. Lucas, Jr., “Mortgages and Monetary Policy”（Wall Street Journal, September 19, 2007）

In the past 50 years, there have been two macroeconomic policy changes in the United States that have really mattered. One of these was the supply-side reduction in marginal tax rates, initiated after Ronald Reagan was elected president in 1980 and continued and extended during the current administration. The other was the advent of "inflation targeting," which is the term I prefer for a monetary policy focused on inflation-control to the exclusion of other objectives. As a result of these changes, steady GDP growth, low unemployment rates and low inflation rates -- once thought to be an impossible combination -- have been a reality in the U.S. for more than 20 years.

Both of these reforms work, in part, because they stabilize people's expectations about aspects of the future. The supply side tax cuts, in contrast to Keynesian on-again-off-again temporary tax cuts, are designed to be in place over the long run, and help to assure us that the returns to today's hard work and savings will not be taxed away tomorrow. Inflation targeting is a commitment that no matter what unpredictable shocks the economy is subjected to, the Fed will do what is needed to restore a fixed, target inflation rate and so maintain a "nominal anchor" to expectations.

This summer's subprime mortgage crisis puts the long-run emphasis of inflation targeting to a severe test. Something has to be done right now. What should it be?

By reducing the discount rate and encouraging use of the discount window -- instead of reducing the funds rate until yesterday -- I think Mr. Bernanke was trying to separate the short-term problem of lender of last resort and the long-term problem of inflation targeting, and to show that we can and will deal forcefully with the liquidity crisis, if one should emerge, without weakening the commitment to price stability.

The need for a lender-of-last-resort function is one qualification to the discipline of inflation targeting, but it is a necessary one. There is a second line of argument that seems to me much less compelling. It starts with the fact that monetary policy necessarily affects future inflation rates, not the current rate: That has already been determined when the open market committee meets. We also know that whatever funds rate target is chosen, all kinds of others forces -- anything that happens to the real economy -- will affect next quarter's rate of inflation, or next year's. So we would like to forecast these other forces as well as possible and take them into account.

There is nothing wrong with this logic, but how useful it is depends on how good we are at forecasting the non-monetary determinants of prices. In fact, inflation forecasting is notoriously one of the squishiest areas of economic statistics. In this situation, it is all too easy for easy money advocates to see a recession coming and rationalize low interest rates. They could be right -- who really knows? -- and in any case we may not know enough to prove them wrong.

To me, inflation targeting at its best is an application of Milton Friedman's maxim that "inflation is always and everywhere a monetary phenomenon," and its corollary that monetary policy should concentrate on the one thing it can do well -- control inflation. It can be hard to keep this in mind in financially chaotic times, but I think it is worth a try.

一年前の論説だけれども、単なる時論にとどまらない（＝状況を超えた普遍性を有する）議論が展開されております。
ルーカス先生は現在の状況をどのように見てらっしゃるんだろうか。

大不況は再来するか

●Gregory Mankiw, “But Have We Learned Enough?”（New York Times, October 25, 2008）

But when Olivier Blanchard, the I.M.F.’s chief economist, was asked about the possibility of the world sinking into another Great Depression, he reassuringly replied that the chance was “nearly nil.” He added, “We’ve learned a few things in 80 years.”

LOOKING back at these events, it’s hard to avoid seeing parallels to the current situation. Today, as then, uncertainty has consumers spooked. By some measures, stock market volatility in recent days has reached levels not seen since the 1930s. With volatility spiking, the University of Michigan’s survey reading of consumer sentiment has been plunging.

Deflation across the economy is not a problem (yet), but deflation in the housing market is the source of many of our present difficulties. With so many homeowners owing more on their mortgages than their houses are worth, default is an unfortunate but often rational choice. Widespread foreclosures, however, only perpetuate the downward spiral of housing prices, further defaults and additional losses at financial institutions.

The Fed and the Treasury Department, intent on avoiding the early policy inaction that let the Depression unfold, have been working hard to keep credit flowing. But the financial situation they face is, arguably, more difficult than that of the 1930s. Then, the problem was largely a crisis of confidence and a shortage of liquidity. Today, the problem may be more a shortage of solvency, which is harder to solve.

Let me be clear: Like Mr. Blanchard at the I.M.F., I am not predicting another Great Depression. We have indeed learned a lot over the last 80 years. But you should take that economic forecast, like all others, with more than a single grain of salt.

今般の金融危機と1930年代の大不況（Great Depression）との推移が類似していることもあって、「すわっ！　大不況の再来か」と悲観的になってしまうのも無理はない。私（＝マンキュー）はブランシャールと同じく1930年代並みの不況が再来することはないだろうと予測するけれども、経済学者の予測を過度に信頼するのも考えものだよ、とのこと。

1930年代の大不況時のように政府（中央銀行含む）が事態をさらに悪化させる（あるいは不況を後押しする）ようなことはないだろう（＝例えば不況期に非効率的な企業を市場から退出させることを目的として政府予算の縮小・金融引き締めが実施されるようなことはないだろう）、とどこの馬の骨ともわからない私は予測しますが*1、この予測は自分で言うのもなんだけど信じないほうがいいと思う。というのも、何もしないことが時に不況の深化に手を貸すことになるとすれば（積極的な景気悪化の原因とまではいえないかもしれないけれども）、某極東の島国においてすでにこの予測は外れてるような気がしないでもないから。

*1:たぶんマンキューもこの点は同意してくれるだろうと思う。“The Fed and the Treasury Department, intent on avoiding the early policy inaction that let the Depression unfold”という文章から推測する限り。