Mankiw [1982] explores the Permanent Income Hypothesis implication that durable expenditures follow an ARMA(1,1) representation. He finds that durable expenditures are represented by an AR(1) process which implies that the rate of depreciation of durables, under the PIH model, is 100%. This...

We introduce a computationally tractable dynamic equilibrium model of the automobile market where new and used cars of multiple types (e.g. makes/models) are traded by heterogeneous consumers. Prices and quantities are determined endogenously to equate supply and demand for all car types and...

We push the span of hedonic price calculations for automobiles backwards towards the industry's birth. Most of the real change that occurred between 1906 and 1982 occurred between 1906 and 1940. During these years, hedonic prices fell at an average annual rate of 5%. The pace was brisker still...

Product redesigns happen across virtually all types of products. While there is substantial evidence that new varieties of goods increase welfare, there is little evidence on the effect of product redesigns. We develop a model of redesign and exit decisions in a dynamic oligopoly model (a la...

We examine the sensitivity of simple calibration models of trade in imperfectly competitive industries to changes in model specification, as well as to changes in the calibration parameters. We find that not just the magnitude, but also the sign of the optimal trade policies is very sensitive to...

The number of different car and light truck models produced in North America has increased enormously over the last decades. The data suggests that producing this increased variety of vehicles is associated with a productivity penalty. We show that manufacturers can adopt complementary...

Regional trade agreements must specify domestic-content rules (rules of origin) that define the conditions under which a good qualifies as 'domestic' and so may be freely traded within the block. The paper analyzes such rules, focussing in particular on oligopolistic industries in which foreign...

This paper studies the causal mechanisms behind persistent poverty. Using original data on Boran pastoralists of southern Ethiopia, we find that heterogeneous and nonlinear wealth dynamics arise purely in adverse states of nature. In favorable states, expected herd grow is quasi-linear and...

This paper introduces a method for solving numerical dynamic stochastic optimization problems that avoids rootfinding operations. The idea is applicable to many microeconomic and macroeconomic problems, including life cycle, buffer-stock, and stochastic growth problems. Software is provided