Knowledge that Transforms

In the last few years, a new area has emerged in economic theory, which goes under the heading of 'incomplete contracting'. However, almost since its inception, the theory has been under attack for its lack of rigorous foundations. In this paper we evaluate some of the criticisms that have been made of the theory, in particular, those in Maskin and Tirole (1998a). In doing so, we develop a model that provides a rigorous foundation for the idea that contracts are incomplete.

This paper studies a dynamic model of a financial market with N strategic agents. Agents receive random stock endowments at each period and trade to share dividend risk. Endowments are the only private information in the model. We find that agents trade slowly even when the time between trades goes to 0. In fact, welfare loss due to strategic behaviour increases as the time between trades decreases. In the limit when the time between trades goes to 0, welfare loss is of order 1/N, and not 1/N2 as in the static models of the double auctions literature. The model is very tractable and closed-form solutions are obtained in a special case.

This paper analyses the equilibrium dynamics of an endogenous growth model with physical and human capital in which leisure enters the utility function. The inclusion of leisure introduces a potential source of non-convexities in our optimization problem and leads to the possible existence of multiple balanced growth paths. This multiplicity of optimal stationary solutions is linked to the assumption that education has no effect on the quality of leisure, and hence a relatively more educated economy may choose to grow faster, and devote more time to income-directed activities. To characterize the set of optimal solutions in our non-concave optimization framework we develop a new method of analysis that should be of interest in related applications.

The paper studies how a person's concern for a future career may influence his or her incentives to put in effort or make decisions on the job. In the model, the person's productive abilities are revealed over time through observations of performance. There are no explicit output-contingent contracts, but since the wage in each period is based on expected output and expected output depends on assessed ability, an “implicit contract” links today's performance to future wages. An incentive problem arises from the person's ability and desire to influence the learning process, and therefore the wage process, by taking unobserved actions that affect today's performance. The fundamental incongruity in preferences is between the individual's concern for human capital returns and the firm's concern for financial returns. The two need be only weakly related. It is shown that career motives can be beneficial as well as detrimental, depending on how well the two kinds of capital returns are aligned.

This paper presents an approximate analytical solution to the optimal consumption and portfolio choice problem of an infinitely lived investor with Epstein-Zin-Weil utility who faces a constant riskless interest rate and a time-varying equity premium. When the model is calibrated to U. S. stock market data, it implies that intertemporal hedging motives greatly increase, and may even double, the average demand for stocks by investors whose risk-aversion coefficients exceed one. The optimal portfolio policy also involves timing the stock market. Failure to time or to hedge can cause large welfare losses relative to the optimal policy.

Recently, several central banks have lost their bank supervisory responsibilities, in part because it has not been shown that supervisory authority improves the conduct of monetary policy. This paper finds that confidential bank supervisory information could help the Board staff more accurately forecast important macroeconomic variables and is used by FOMC members to guide monetary policy. These findings suggest that the complementarity between supervisory responsibilities and monetary policy should be an important consideration when evaluating the structure of the central bank.

We present a model that links heterogeneity of preferences across ethnic groups in a city to the amount and type of public goods the city supplies. We test the implications of the model with three related data sets: U. S. cities, U. S. metropolitan areas, and U. S. urban counties. Results show that the shares of spending on productive public goods—education, roads, sewers and trash pickup—in U. S. cities (metro areas/urban counties) are inversely related to the city's (metro area's/county's) ethnic fragmentation, even after controlling for other socioeconomic and demographic determinants. We conclude that ethnic conflict is an important determinant of local public finances.

We examine the impact of increased abortion availability on the average living standards of children through a selection effect. Would the marginal child who was not born have grown up in different circumstances than the average child? We use variation in the timing of abortion legalization across states to answer this question. Cohorts born after legalized abortion experienced a significant reduction in a number of adverse outcomes. We find that the marginal child would have been 40–60 percent more likely to live in a single-parent family, to live in poverty, to receive welfare, and to die as an infant.

Do professional forecasters provide their true unbiased estimates, or do they behave strategically? In our model, forecasters have common information, confer actively, and thus know the true pdf of future outcomes. Intensive users of economic forecasts monitor forecasters' performance closely; occasional users are drawn to the forecaster who fared best in the previous period. In the resulting Nash equilibrium, even though economists have identical expectations, they make a range of projections that mimics the true probability distribution of the forecast variable. Those whose wages depend most on publicity produce forecasts that differ most from the consensus. Empirical evidence supports the model.

This paper develops a simple macroeconomic model that shows that combin-ing capital market imperfections together with unequal access to investment opportunities across individuals can generate endogenous and permanent fluctua-tions in aggregate GDP, investment, and interest rates. Reducing inequality of access may be a necessary condition for macroeconomic stabilization. Moreover, countercyclical fiscal policies have a role to play: in our model savings are underutilized in slumps because of the limited debt capacity of potential investors. Therefore, the government should issue public debt during recessions in order to absorb those idle savings and finance investment subsidies or tax cuts for investors. The most important single fact about saving and investment activities is that in our industrial society they are generally done by different people and for different reasons. (...) For years there might tend to be too little investment, leading to deflation, losses, excess capacity and unemployment. For other years, there might tend to be too much investment, leading to periods of chronic inflation—unless prudent and proper public policies in the fiscal and monetary fields are followed [Paul A. Samuelson, Economics 8th edition, 1970, pp. 196–198].