Technology shocks and the business cycle

Business cycles

Some comments on the role of econometrics in economic theory

The basic tension facing econometricians is that structural models are necessary for addressing monetary policy questions. But all models are, by their very nature, false. Econometric programs that focus on testing whether models are true will be ignored by practicing macroeconomists. The critical task facing econometricians is to develop diagnostic tools for assessing the usefulness of models for addressing particular questions. This article reviews two diagnostic strategies.Econometrics ; Economics

Complementary Roles of Hippocampus and Medial Entorhinal Cortex in Episodic Memory

Spatial mapping and navigation are figured prominently in the extant literature that describes hippocampal function. The medial entorhinal cortex is likewise attracting increasing interest, insofar as evidence accumulates that this area also contributes to spatial information processing. Here, we discuss recent electrophysiological findings that offer an alternate view of hippocampal and medial entorhinal function. These findings suggest complementary contributions of the hippocampus and medial entorhinal cortex in support of episodic memory, wherein hippocampal networks encode sequences of events that compose temporally and spatially extended episodes, whereas medial entorhinal networks disambiguate overlapping episodes by binding sequential events into distinct memories.National Institute of Mental Health Grants (MH51570, MH071702); National Science Foundation (Science of Learning Center grant SBE-0354378

Fiscal policy in the aftermath of 9/11

This paper investigates the nature of U.S. fiscal policy in the aftermath of 9/11. We argue that the recent dramatic fall in the government surplus and the large fall in tax rates cannot be accounted for by either the state of the U.S. economy as of 9/11 or as the typical response of fiscal policy to a large exogenous rise in military expenditures. Our evidence suggests that, had tax rates responded in the way they ‘normally’ do to large exogenous changes in government spending, aggregate output would have been lower and the surplus would not have changed by much. The unusually large fall in tax rates had an expansionary impact on output and was the primary force underlying the large decline in the surplus. Our results do not bear directly on the question of whether the decline in tax rates and the decline in the surplus after 9/11 were desirable or not.Fiscal policy ; Terrorism

Identification and the Liquidity Effect of a Monetary Policy Shock

Conventional wisdom holds that unanticipated expansionary monetary policy shocks cause transient but persistent decreases in real and nominal interest rates. However a number of econometric studies argue that the evidence favors the opposite view, namely that these shocks actually raise, rather than lower, short term interest rates. We show that this conclusion is not robust to the measure of monetary aggregate used or to the assumptions made to identify monetary policy disturbances. For example, when our analysis is done using non borrowed reserves, we find strong evidence in favor of the conventional view. Existing challenges to the conventional view lack credibility not just because of their fragility. They are based upon measures of policy disturbances which generate seemingly implausible implications about things other than interest rates.

How does an increase in government purchases affect economy?

This article studies the impact on aggregate economic activity of increases in defense purchases which are unrelated to other developments in the economy. The authors use empirical evidence to evaluate the predictions of several prominent models.Economic development ; Macroeconomics ; Labor market ; Expenditures, Public ; Defense industries

Evaluating the Calvo model of sticky prices

This paper studies the empirical performance of a widely used model of nominal rigidities: the Calvo model of sticky goods prices. We describe an extended version of this model with variable elasticity of demand of the differentiated goods and imperfect capital mobility. We find little evidence against standard versions of the model without the extensions, but the estimated frequency of price adjustment is implausible. With the extended model the estimates are more reasonable. This is especially so if the sample is split to take into account a possible change in monetary regime around 1980.Prices

Testing the Calvo model of sticky prices

This article discusses the empirical performance of a widely used model of nominal rigidities: the Calvo model of sticky good prices. The authors argue that there is overwhelming evidence against this model. But this evidence is generated under three key assumptions: one, there is no lag between the time firms reoptimize their price plans and the time they implement those plans; two, there is no measurement error in inflation; and three, monetary policy is the same in the pre-1979 and post-1982 periods. The authors discuss the impact of relaxing each of these assumptions.Prices ; Macroeconomics