The first, described as the St Louis Fed’s new characterisation of the economy, is here. In it, Mr Bullard says that there can be multiple productivity regimes—low and high, for instance, corresponding to slower or faster trend growth—but that the Fed has no way to predict when a move from one to another will occur (and should not try to in making its projections). There can also be multiple real interest rate regimes, based on things like the supply and demand for capital and the liquidity premium on safe assets. The interest-rate regime also seems to be persistent, with switches that can’t easily be predicted. For the economy to look wildly different from its current state, one of those two factors, productivity and real interest rates, would need to flip to some new regime. But they probably won’t, Mr Bullard says, and so the economy probably won’t look wildly different. 

characterisation：特徴の説明
productivity regime：生産性の体制
liquidity premium：流動性プレミアムとは、流動性の低い有価証券に付加されるプレミアムのこと。 一般に長期債券の方が、短期債券よりも利回りが高くなるが、これは長期債券の利回りに流動性プレミアムが付加されているからだと説明される。
capital-safe asset：資本保証資産 
persistent：長続きする
switch：乗り換え
flip to：変わる

That story is interesting, but not especially monetary. Reading it one suspects there are more things going on in the background. And there might well be. In another piece published this month, Mr Bullard posits a very different sort of regime-based world. It is one that is rooted in the “Neo-Fisherian” ideas (so called because of their relation to the work of Irving Fisher) recently developed by John Cochrane, of the University of Chicago. Neo-Fisherians make a pretty simple point: nominal interest rates in an economy are a function of both the underlying real interest rate and the expected rate of inflation. The real interest rate is determined by markets and will converge over time to some natural rate. That implies that if a central bank sets a particular nominal interest rate, the long-run inflation rate is necessarily pinned down. And that, in turn, implies that if central banks raise interest rates dramatically, that will eventually and inevitably lead to high inflation. 

posit：だと仮定する・断定する
The Neo-Fisherian Proposition： The Neo-Fisherian proposition is that a persistent policy-induced increase in short-term nominal interest rates will lead to higher inflation in the long-run.
necessarily ：必然的に

One way of looking at recent macroeconomic experience, suggests Mr Bullard, is that the Fed has been targeting a near-zero interest rate. With the nominal interest rate effectively pegged at zero, inflation was inevitably going to settle into a lower regime. It has done so. While it remains in that regime, Mr Bullard says, long-run real economic growth will mostly depend on fundamentals—that is, on the productivity regime. Meanwhile, most central banks will find themselves needed to rely on quantative easing to address any future shocks to demand. 

This is all very interesting, but I think the conclusions Mr Bullard draws are a little off. Start, though, with where he is correct. The Fed cannot predict changes in productivity, and neither can monetary policy affect long-run real economic growth. It wouldn’t make sense for the Fed to target real GDP growth, but then, the Fed is not really in that business. The Fed is also unable to control the long-run real interest rate, which is a function of global saving and investment. What’s more, it does seem clear that the global real interest rate has settled down to a level of approximately zero. 

But does it follow that the Fed should then either 1) set a high nominal interest rate in order to achieve higher inflation, or 2) keep its interest rate low and accept low inflation? I don’t believe so. 

水曜日。Bullard氏の見解を分析している。Neo-Fisherianの等式では金利が上がればインフレもそれに伴うと言っているが、長期的な経済の成長は生産性に依存する。そのために需要を喚起するために金融緩和をしている。ただ、Fedはその生産性を変えることはできないし、金融政策が長期的な成長に影響を与えることはできない。要は長期の実質金利をFedが管理することはできないと言っている。そうは言っても、このNeo-Fisherianの等式を考えると名目金利を上げるべきなのだろうかという議論をしている。

昨日の昼は有澤さんと栗林さんとの会食を豊洲で行った。夜は神谷さんのオープンフォーラムに参加させてもらった。そうそうたるメンバーの中に加えてもらった。楽しいひと時だった。家に帰ったら１２時を回っていた。今日も海野塾があるので、夜が遅い。今週は土曜日まで毎日だ。体が持たないが、楽しい毎日だ。ではまた明日。