Research Database

We document and attempt to explain the observation that automobile insurance premiums vary dramatically across local markets. We argue high premiums can be attributed to the large numbers of uninsured motorists in some cities, while at the same time, the uninsured motorists can be attributed to high premiums. We construct a simple noncooperative equilibrium model, where limited liability can generate inefficient equilibria with uninsured drivers and high, yet actuarially fair, premiums. For certain parameterizations, an optimal full insurance equilibrium and inefficient high price equilibria with uninsured drivers exist simultaneously, consistent with the observed price variability across seemingly similar cities.

Monetary policy instruments differ in tightness—how closely they are linked to inflation—and transparency—how easily they can be monitored. Tightness is always desirable in a monetary policy instrument; when is transparency? When a government cannot commit to follow a given policy. We apply this argument to a classic question: Is the exchange rate or the money growth rate the better monetary policy instrument? We show that if the instruments are equally tight and a government cannot commit to a policy, then the exchange rate’s greater transparency gives it an advantage as a monetary policy instrument.

Between 1929 and 1933, real output per adult fell over 30 percent and total factor productivity fell 18 percent. This productivity decrease is much larger than expected from just extrapolating the productivity decrease that typically occurs during recessions. This paper evaluates what factors may have caused this large decrease, including unmeasured factor utilization, changes in the composition of production, and increasing returns. I find that these factors combined explain less than one-third of the 18 percent decrease, and I conclude that the productivity decrease during the Great Depression remains a puzzle.

We study decentralized learning in organizations. Decentralization is captured through a symmetry constraint on agents’ strategies. Among such attainable strategies, we solve for optimal and equilibrium strategies. We model the organization as a repeated game with imperfectly observable actions. A fixed but unknown subset of action profiles are successes and all other action profiles are failures. The game is played until either there is a success or the time horizon is reached. For any time horizon, including infinity, we demonstrate existence of optimal attainable strategies and show that they are Nash equilibria. For some time horizons, we can solve explicitly for the optimal attainable strategies and show uniqueness. The solution connects the learning behavior of agents to the fundamentals that characterize the organization: Agents in the organization respond more slowly to failure as the future becomes more important, the size of the organization increases and the probability of success decreases.

This paper provides a quantitative assessment of the effects of inflation through changes in the value of nominal assets. We document nominal positions in the U.S. across sectors as well as different groups of households, and estimate the redistribution brought about by a moderate inflation episode. Redistribution takes the form of “ends-against-the-middle:” the middle class gains at the cost of the rich and poor. In addition, inflation favors the young over the old, and hurts foreigners. A calibrated OLG model is used to assess the macroeconomic implications of this redistribution under alternative fiscal policy rules. We show that inflation-induced redistribution has a persistent negative effect on output, but improves the weighted welfare of domestic households.

We study the effects of large transportation costs on economic development. We argue that the Midwest and the Northeast of the U.S. is a natural case because starting from 1840 decent data is available showing that the two regions shared key characteristics with today’s developing countries and that transportation costs were large and then came way down. To disentangle the effects of the large reduction in transportation costs from those of other changes that happened during 1840–1860, we build a model that speaks to the distribution of people across regions and across the sectors of production. We find that the large reduction in transportation costs was a quantitatively important force behind the settlement of the Midwest and the regional specialization that concentrated agriculture in the Midwest and industry in the Northeast. Moreover, we find that it led to the convergence of the regional per capita incomes measured in current regional prices and that it increased real GDP per capita. However, the increase in real GDP per capita is considerably smaller than that resulting from the productivity growth in the nontransportation sectors.

We show how to use panel data on household consumption to directly estimate households’ risk preferences. Specifically, we measure heterogeneity in risk aversion among households in Thai villages using a full risk-sharing model, which we then test allowing for this heterogeneity. There is substantial, statistically significant heterogeneity in estimated risk preferences. Full insurance cannot be rejected. As the risk sharing, as-if-complete-markets theory might predict, estimated risk preferences are unrelated to wealth or other characteristics. The heterogeneity matters for policy: Although the average household would benefit from eliminating village-level risk, less-risk-averse households who are paid to absorb that risk would be worse off by several percent of household consumption.

No abstract available.

This paper catalogues formulas that are useful for estimating dynamic linear economic models. We describe algorithms for computing equilibria of an economic model and for recursively computing a Gaussian likelihood function and its gradient with respect to parameters. We apply these methods to several example economies.

This paper presents a simple general equilibrium model of optimal taxation in which both private agents and the government can default on their debt. As a benchmark we consider Ramsey equilibria in which the government can precommit to its policies at the beginning of time, but in which private agents can default. We then consider sustainable equilibria in which both government and private agent decision rules are required to be sequentially rational. We completely characterize the set of sustainable equilibria. In particular, we show that when there is sufficiently little discounting and government consumption fluctuates enough, the Ramsey allocations and policies (in which the government never defaults) can be supported by a sustainable equilibrium.