We develop a framework for valuing improvements in health and apply it to past and prospective reductions in mortality in the United States. We calculate social values of (i) increased longevity over the twentieth century, (ii) progress against various diseases after 1970, and (iii) potential future progress against major diseases. Cumulative gains in life expectancy after 1900 were worth over $1.2 million to the representative American in 2000, whereas post-1970 gains added about $3.2 trillion per year to national wealth, equal to about half of GDP. Potential gains from future health improvements are also large; for example, a 1 percent reduction in cancer mortality would be worth $500 billion.

We study the extent to which U. S. urban development is sprawling and what determines differences in sprawl across space. Using remote-sensing data to track the evolution of land use on a grid of 8.7 billion 30 × 30 meter cells, we measure sprawl as the amount of undeveloped land surrounding an average urban dwelling. The extent of sprawl remained roughly unchanged between 1976 and 1992, although it varied dramatically across metropolitan areas. Ground water availability, temperate climate, rugged terrain, decentralized employment, early public transport infrastructure, uncertainty about metropolitan growth, and unincorporated land in the urban fringe all increase sprawl.

This paper analyzes a marked change in the evolution of the U.S. wage structure over the past fifteen years: divergent trends in upper-tail (90/50) and lower-tail (50/10) wage inequality. We document that wage inequality in the top half of distribution has displayed an unchecked and rather smooth secular rise for the last 25 years (since 1980). Wage inequality in the bottom half of the distribution also grew rapidly from 1979 to 1987, but it has ceased growing (and for some measures actually narrowed) since the late 1980s. Furthermore we find that occupational employment growth shifted from monotonically increasing in wages (education) in the 1980s to a pattern of more rapid growth in jobs at the top and bottom relative to the middles of the wage (education) distribution in the 1990s. We characterize these patterns as the %u201Cpolarization%u201D of the U.S. labor market, with employment polarizing into high-wage and low-wage jobs at the expense of middle-wage work. We show how a model of computerization in which computers most strongly complement the non-routine (abstract) cognitive tasks of high-wage jobs, directly substitute for the routine tasks found in many traditional middle-wage jobs, and may have little direct impact on non-routine manual tasks in relatively low-wage jobs can help explain the observed polarization of the U.S. labor market.

We examine whether nonprofit organizations understate fundraising expenses in their publicly available financial statements. A large body of anecdotal evidence notes that an inexplicable number of nonprofits report zero fundraising expenses. We provide empirical evidence that the zero fundraising expense phenomenon is at least partly due to inappropriate reporting. We then examine to what extent these misreported expenses are the result of managerial incentives. Prior research finds an association between reported expenses and managerial compensation as well as the level of donations received. Using these findings we construct two incentive variables and find a positive association between misreporting behavior and managerial incentives. Our results also suggest that the use of an outside accountant reduces the probability that a nonprofit will misreport expenses, consistent with the use of an outside paid accountant increasing the reliability and usefulness of nonprofit financial reports. Finally, we find that SOP 98-2 reduced the probability that a nonprofit will misreport fundraising expenses.

To address agents' moral hazard over effort, incentive contracts impose risk on the agents. As performance measures become noisier, the conventional agency analysis predicts that principals will reduce the incentive weights assigned to such measures. However, prior empirical results (Prendergast 2002) frequently find the opposite, i.e., incentive weights are larger (agents bear more risk) in more uncertain environments. This paper provides new evidence on the association between the extent of uncertainty and the level of risk imposed on agents. In the context of contracts between managed care organizations and physicians, we examine the effect of task characteristics and the legal liability environment on the extent of risk that physicians bear. We derive the optimal weighting of multiple performance measures in a model of a physician's choice of revenue-generating and cost-control efforts. The model predicts that physicians who face less task uncertainty bear more cost risk in their contracts, as predicted by the conventional moral hazard model. Likewise, the model predicts that as the association between task uncertainty and legal liability uncertainty becomes stronger, physicians bear less cost risk in their contracts. Our empirical results generally support these predictions. We offer an explanation for why these results tend to be consistent with the conventional moral hazard analysis, contrary to empirical results in a number of previous studies.

We consider a competitive and perfect financial market in which agents have heterogeneous cash flow valuations. Instead of assuming that agents are endowed with rational expectations, we model their behavior as the product of adaptive learning. Our results demonstrate that adaptive learning affects security design profoundly, with securities mispriced even in the long run and optimal designs trading off underpricing against intrinsic value maximization. The evolutionary dominant security design calls for issuing securities that engender large losses with a small but positive probability, but that otherwise produce stable payoffs, almost the exact opposite of the pure state claims that are optimal in the rational expectations framework.