Knowledge that Transforms

We study an overlapping generations version of the principal-agent problem, where incentive contracts are determined in general equilibrium. All individuals are workers when young, but have a choice between becoming entrepreneurs or remaining workers when old. Imperfections in the credit market give rise to rents in entrepreneurial activities involving capital. These rents motivate poor young agents to work hard and save to overcome the borrowing constraints. With a labour market that is subject to moral hazard, the increased effort raises social welfare. Policies that reduce credit market imperfections, or redistribute income, may reduce welfare by dampening this effect.

The changes in the distribution of earnings during the 1980s have been studied extensively. The two most striking characteristics of the decade are (a) a large increase in the college/high school wage gap, and (b) a substantial rise in the variance of wage residuals. While this second phenomenon is typically implicitly attributed to an increase in the demand for unobserved skill, most work in this area fails to acknowledge that this same increase in demand for unobserved skill could drive the evolution of the measured college premium. In its simplest form, if higher ability individuals are more likely to attend college, then the increase in the college wage premium may be due to a increase in the relative demand for high ability workers rather than an increase in the demand for skills accumulated in college. This paper develops and estimates a dynamic programming selection model in order to investigate the plausibility of this explanation. The results are highly suggestive that an increase in the demand for unobserved ability could play a major role in the growing college premium.

I analyse a model that explicitly incorporates local interactions and allows agents to exchange information about job openings within their social networks. Agents are more likely to be employed if their social contacts are also employed. The model generates a stationary distribution of unemployment that exhibits positive spatial correlations. I estimate the model via an indirect inference procedure, using Census Tract data for Chicago. I find a significantly positive amount of social interactions across neighbouring tracts. The local spillovers are stronger for areas with less educated workers and higher fractions of minorities. Furthermore, they are shaped by ethnic dividing lines and neighbourhood boundaries.

Contract design under incomplete information is often analysed in a bilaterally monopolistic setting. If the informed party’s reservation value does not depend on its private information (its type), it is a standard result that the uninformed side offers "low" types distorted contracts to reduce the information rent left to "high" types. We challenge this result by embedding contract design in a matching market environment. We consider a market where players meet pairwise and where, in each match, either side may be chosen to make a take-it-or-leave-it offer. As frictions become sufficiently low, we find that the set of equilibria is independent of whether there is complete or incomplete information. In particular, all contracts are free of distortions.

It is widely thought that incomes risks can be shared by trading in financial assets. But financial assets typically carry some risk idiosyncratic to them, hence, disposing incomes risk using financial assets will involve buying into the inherent idiosyncratic risk. However, standard theory argues that diversification would reduce the inconvenience of idiosyncratic risk to arbitrarily low levels. This paper shows that this argument is not robust: ambiguity aversion can exacerbate the tension between the two kinds of risks to the point that classes of agents may not want to trade some financial assets. Thus, theoretically, the effect of ambiguity aversion on financial markets is to make the risk sharing opportunities offered by financial markets less complete than it would be otherwise.

A seller with two objects faces a group of bidders who are subject to budget constraints. The objects have common values to all bidders but need not be identical, and may be either complements or substitutes. In a simple complete information setting we show: (1) if the objects are sold by means of a sequence of open ascending auctions, then it is always optimal to sell the more valuable object first; (2) the sequential auction yields more revenue than the simultaneous ascending auction used recently by the FCC if the discrepancy in the values is large, or if there are significant complementarities; (3) a hybrid simultaneous-sequential form is revenue superior to the sequential auction; and (4) budget constraints arise endogenously.

Workers face a trade-off between macroeconomic and individual incentives to work in different occupations/industries; namely, between search frictions and personal comparative advantages. Workers endowed with heterogeneous multi-dimensional skills search for jobs that require different skill combinations. In equilibrium, specialized individuals contact few, selected types of vacancies, where they are likely to be hired; those with weak comparative advantages are seldom chosen among competing applicants, thus seek any job type. In a tight labour market, comparative advantages dominate waiting costs: offsetting labour mobility across industries/occupations—Excess Worker Reallocation—is lower and matches are more successful, consistently with direct and indirect evidence.

We analyse a market where (i) trade proceeds by random and anonymous pairwise meetings with bargaining; (ii) agents are asymmetrically informed about the value of the traded good; and (iii) no new entrants are allowed once the market is open. We show that information revelation and efficiency never obtain in equilibrium, even as discounting is removed. This holds whether the asymmetry is two-sided or one-sided. In some cases there exist equilibria where a substantial amount goes untraded. This contrasts with the earlier literature, which was based on the steadystate equilibria of a model where agents enter the market every period.

Balanced growth models are commonly used in macroeconomics because they are consistent with the well-known Kaldor facts regarding economic growth. These models, however, are inconsistent with one of the most striking regularities of the growth process—the massive reallocation of labour from agriculture into manufacturing and services. This paper presents a simple model consistent with both the Kaldor facts and the dynamics of sectoral labour reallocation.

Car prices in Europe are characterized by large and persistent differences across countries. The purpose of this paper is to document and explain this price dispersion. Using a panel data set extending from 1980 to 1993, we first demonstrate two main facts concerning car prices in Europe: (1) The existence of significant differences in quality adjusted prices across countries, with Italy and the U.K. systematically representing the most expensive markets. (2) Substantial year-to-year volatility that is to a large extent accounted for by exchange rate fluctuations and the incomplete response of local currency prices to these fluctuations. These facts are analysed within the framework of a multiproduct oligopoly model with product differentiation. The model identifies three potential sources for the international price differences: price elasticities generating differences in markups, costs, and import quota constraints. Local currency price stability can be attributed either to the presence of a local component in marginal costs, or to markup adjustment that is correlated with exchange rate volatility; the latter requires that the perceived elasticity of demand is increasing in price. We find that the primary reason for the higher prices in Italy is the existence of a strong bias for domestic brancs that generates high markups for the domestic firm (Fiat). In the U.K. higher prices are mainly attributed to better equipped cars and/or differences in the dealer discount practices. The import quota constraints are found to have a significant impact on Japanese car prices in Italy, France and the U.K. With respect to local currency price stability, a large percentage of the documented price inertia can be attributed to local costs, and a smaller fraction to markup adjustment that is indicative of price discrimination. Based on these results we conjecture that the EMU will substantially reduce the year-to-year volatility observed in the car price data, but without further measures to increase European integration, it will not completely eliminate existing cross-country price differences.