ECONOMIC EFFECTS OF CURRENCY UNIONS

We develop a new instrumental-variable (IV) approach to estimate the effects of different exchange rate regimes on bilateral outcomes. The basic idea is that the characteristics of the exchange rate between two countries are partially related to the independent decisions of these countries to peg—explicitly or de facto—to a third currency, notably that of a main anchor. This component of the exchange rate regime can be used as an IV in regressions of bilateral outcomes. We apply the methodology to study the economic effects of currency unions. The likelihood that two countries independently adopt the currency of the same anchor country is used as an instrument for whether they share a common currency. We find that sharing a common currency enhances trade, increases price comovements, and decreases the comovement of real gross domestic product shocks. ( JEL C3, F3, F4)     

Using a Markov Chain to Construct a Tractable Approximation of an Intractable Probability Distribution

Abstract.  Let π denote an intractable probability distribution that we would like to explore. Suppose that we have a positive recurrent, irreducible Markov chain that satisfies a minorization condition and has π as its invariant measure. We provide a method of using simulations from the Markov chain to construct a statistical estimate of π from which it is straightforward to sample. We show that this estimate is 'strongly consistent' in the sense that the total variation distance between the estimate and π converges to 0 almost surely as the number of simulations grows. Moreover, we use some recently developed asymptotic results to provide guidance as to how much simulation is necessary. Draws from the estimate can be used to approximate features of π or as intelligent starting values for the original Markov chain. We illustrate our methods with two examples.     

ADDICTION, COMPULSION, AND THE TECHNOLOGY OF CONSUMPTION

The consumption technology model of Lancaster and Becker is extended to include addictive activities. Assuming a utility function in which the individual places a premium on maintenance of self-esteem, the model generates empirically verified patterns of habituation, withdrawal, and the compulsive restarting of an abandoned habit. It is then applied to the analysis of public policies toward drug abuse. Their frequent ineffectiveness is shown to result from an unwarranted emphasis on deterring the addictive activity rather than on encouraging atceptable behavior.     

EXCESS DEMAND AND MARKET ADJUSTMENT

This paper develops a model of wage and price adjustment that is based on the optimizing behavior of firms. The output of the model is a relationship between price changes and excess demands that looks like a generalized Walrasian adjustment but which is based on firm microfoundations. The model is then applied to stability analysis and the "Phillips curve," using restrictions derived from the underlying optimization to generate results.