Title: Prices and exchange rates in general equilibrium
Description: This thesis examines the dynamics of prices and exchange rates. Chapter 1, written jointly with Emi Nakamura, documents the extent of price rigidity in the United States using the micro data that underlie the consumer and producer price indices for the time period 1988-2005. We find that the median frequency of non-sale price change is 9-12% per month, roughly half of what it is including sales. This implies an uncensored median duration of regular prices of 8-11 months. The median frequency of price change for finished goods producer prices is roughly 11% per month. For certain product categories, we find that the main source of price adjustment is not price changes for identical items; rather most price adjustment is associated with product turnover. We also investigate how the frequency of price change varies with the overall inflation rate, seasonality in the frequency of price change and the hazard function of price changes. Chapter 2, written jointly with Emi Nakamura, investigates how the large amount of heterogeneity in the frequency of price change across sectors in the United States affects the degree of monetary non-neutrality in the U.S. economy. We calibrate a multi-sector menu cost model using the cross-sectional distribution of the frequency and size of price changes in the U.S. economy documented in chapter 1. The degree of monetary non-neutrality implied by this multi-sector model is triple that implied by a one-sector model calibrated to the mean frequency of price change of all firms. We incorporate intermediate inputs into our model. This feature generates a substantial amount of real rigidity, which also roughly triples the degree of monetary non-neutrality in the model without affecting the size of price changes. Together these two features therefore raise the degree of monetary non-neutrality implied by menu cost models by roughly an order of magnitude.

We also study an extension of the model in which firms randomly have an opportunity to change prices for a lower cost than in other periods. We argue that price changes associated with product substitutions can be viewed largely as such exogenous opportunities to change prices. We show that modeling product substitutions in this way yields very different results than if they were treated as regular price changes. Chapter 3 studies the dynamic behavior of real exchange rates both empirically and theoretically. Existing empirical evidence suggests that real exchange rates exhibit hump-shaped dynamics. I show that this is a robust fact across nine large, developed economies. This fact can help explain why existing sticky-price business cycle models have been unable to match the persistence of the real exchange rate. The recent literature has focused on models driven by monetary shocks. In response to monetary shocks, these models yield monotonic impulse responses for the real exchange rate. It is extremely difficult for models that have this feature to match the empirical persistence of the real exchange rate. I show that a standard two-country sticky-price business cycle model yields hump-shaped responses for the real exchange rate to a number of different real shocks. The hump-shaped dynamics generated by the model are a powerful source of endogenous persistence that allows the model to match the long half-life of the real exchange rate.