Working paper (Federal Reserve Bank of Minneapolis. Research Dept.)
We show that some classes of sterilized interventions have no effect on equilibrium prices or quantities. The proof does not depend on complete markets, infinitely-lived agents, Ricardian equivalence, monetary neutrality, or the law of one price. Moreover, regressions of exchange rates or interest differentials on variables measuring the currency composition of the debt may contain no information, in our theoretical economy, about the effectiveness of such interventions. Another class of interventions requires simultaneous changes in monetary and fiscal policy; their effects depend, generally, on the influence of tax distortions, government spending, and money supplies on economic behavior. We suggest that in applying the portfolio balance approach to the study of intervention, lack 01 explicit modeling of these features is a serious flaw.
I prove some theorems for competitive equilibria in the presence of distortionary taxes and other restraints of trade, and use those theorems to motivate an algorithm for (exactly) computing and empirically evaluating competitive equilibria in dynamic economies. Although its economics is relatively sophisticated, the algorithm is so computationally economical that it can be implemented with a few lines in a spreadsheet. Although a competitive equilibrium models interactions between all sectors, all consumer types, and all time periods, I show how my algorithm permits separate empirical evaluation of these pieces of the model and hence is practical even when very little data is available. For similar reasons, these evaluations are not particularly sensitive to how data is partitioned into "trends" and "cycles." I then compute a real business cycle model with distortionary taxes that fits aggregate U.S. time series for the period 1929-50 and conclude that, if it is to explain aggregate behavior during the period, government policy must have heavily taxed labor income during the Great Depression and lightly taxed it during the war. In other words, the challenge for the competitive equilibrium approach is not so much why output might change over time, but why the marginal product of labor and the marginal value of leisure diverged so much and why that wedge persisted so long. In this sense, explaining aggregate behavior during the period has been reduced to a public finance question - were actual government policies distorting behavior in the same direction and magnitude as government policies in the model?