Recent Changes in Macro Policy and Its Effects: Some Time-Series Evidence
利用美国1979年美联储转向准备金目标及1981年政府支持货币主义后的数据，检验政策体制是否变化及其对通胀与失业关系的影响，为评估卢卡斯批判提供实证。
Has the macroeconomic policy changed in the United States in the last few years? If so, has this change had an effect on macroeconomic relationships, and, in particular, on the relationship between inflation and unemployment? These two questions have been on the minds of most macroeconomists since the October 1979 switch from interest rates to reserves as an intermediate target for the Federal Reserve and the explicit endorsement of monetarism by the Reagan Administration in early 1981. The questions are important not only for predicting the course of the economy in the future, but also for assessing the practical significance of the Lucas critique.' According to this critique a change in policy regime should cause changes in the way the economy operates. Comparing economic relations before and after a change in regime should provide a test of the critique. The approach in many recent studies has been to assume that the answer to the first question is yes-that there has been a significant change in the macroeconomic policy regime-and to look for changes in the Phillips curve as a test of the Lucas critique. Thus far, the results have been mixed. Otto Eckstein (1983), Steven Englander and Cornelis Los (1983), and George Perry (1983) conclude that there has been no significant change in the Phillips curve relationship. Phillip Cagan and William Fellner (1983) and Wayne Vroman (1983) find some evidence of a change: wage inflation has come down more quickly-especially in 1982 and early 1983-than would be predicted from a Phillips curve. However, the assumption that there has been a regime change has received little empirical attention. The October 1979 switch from interest rate targetting to reserve targetting at the Fed is usually taken as prima facie evidence of a significant change in policy regime. But such changes in operating procedures per se do not necessarily entail a change in policy regime relevant for macroeconomic purposes. If they did, then the renewed emphasis on interest rates rather than reserves starting in late 1982 should be cited as evidence of a return to the old regime-a view which few researchers have taken. In fact, studies have shown that either interest rates or reserves can be used as intermediate targets for controlling the money supply and ultimately aggregate demand. (The choice between the two depends on whether shocks to the money markets are from the demand side or the supply side.) The issue of importance for assessing whether a regime change has taken place is how much the Fed reacts by adjusting the money supply (appropriately defined) in response to conditions in the economy. The procedure it uses to bring about this response is irrelevant.2 Implicit in a macroeconomic policy regime is a rule relating the money supply to economic con*404 Woodrow Wilson School, Princeton University, Princeton, NJ 08544. This research was supported by a grant from the National Science Foundation at the National Bureau of Economic Research and conducted in part at the Federal Reserve Bank of Philadelphia. I am grateful to Steve Fries for research assistance, and to Steven Englander and Comelis Los for comments on an earlier draft. 'See Robert Lucas (1976). William Fellner's (1978) credibility hypothesis is similar to the Lucas Critique in this context and has been tested in similar ways. 2Some have argued that, for political reasons, by focusing on reserves the Fed would be able to let interest rates go higher than under interest rate targetting. With reserve targetting, Fed officials could shift the blame for high interest rates elsewhere.