Knowledge that Transforms

The random assignment of cadets to social groups at West Point provides a rare opportunity to highlight potentially misleading estimates of social group effects found in many studies. Estimates of contemporaneous group effects in human capital production are typically positive and significant; however, evidence in this study suggests that occurrences common to a group may account for much of this correlation. Models that address these biases provide little evidence of group effects in academic performance, although there is evidence of group influences in choice outcomes such as the selection of academic major and the decision to remain in the Army.

Previous research finds a systematic decrease in consumption at retirement, a finding that is inconsistent with the life cycle/permanent income hypothesis if retirement is an expected event. In this paper, we use workers' subjective beliefs about their retirement dates as an instrument for retirement. After demonstrating that subjective retirement expectations are strong predictors of subsequent retirement decisions, we still find a consumption decline at retirement for workers who retire when expected. However, our estimates of this consumption fall are about a third less than those found when we instead rely on the instrumental variables strategy used in prior studies.

Peer effects have figured prominently in debates on school vouchers, desegregation, ability tracking, and antipoverty programs. Compelling evidence of their existence remains scarce for plaguing endogeneity issues such as selection bias and the reflection problem. This paper is among the first to firmly establish the link between peer performance and student achievement, using a unique data set from China. We find strong evidence that peer effects exist and operate in a positive and nonlinear manner; reducing the variation of peer performance increases achievement; and our semiparametric estimates clarify the trade-offs facing policymakers in exploiting positive peer effects to increase future achievement.

This paper analyzes the pricing behavior of electricity generating firms in the restructured California market from its inception in April 1998 until its collapse in late 2000. Using detailed firm-level data, I find that conduct is fairly consistent with a Cournot pricing game for much of the sample. In summer and fall 2000, the market was slightly less competitive, yet the dramatic rise in prices was more driven by changes in costs and demand than by changes in firm conduct. The five large nonutility generators raised prices slightly above unilateral market-power levels in 2000, but fell far short of colluding on the joint monopoly price.

We show that public investment is dramatically higher in countries with low-quality governance and limited political checks and balances or no competitive elections. This result is robust to a number of specifications. The most plausible interpretation of these results is that these governments use public investment as a vehicle to increase their rent-seeking. This evidence suggests that efforts to increase public investment in countries with weak governance, or to measure the growth effects of productive public investment using only observed measures of public investment, should be undertaken with caution.

A critical question for Social Security policy is how program incentives affect retirement behavior. We use the Health and Retirement Survey (HRS) to examine the impact of Social Security incentives on male retirement. We implement forward-looking models whereby individuals consider the incentives to work in all future years. We find that forward-looking incentive measures for Social Security are significant determinants of retirement. We also find that private pension incentives have roughly similar effects. Our findings suggest that Social Security policies that increase the incentives to work at older ages can significantly reduce the labor force exit rate of older workers.

This paper finds that the use of price controls has a statistically and quantitatively important effect on the extent and timing of the launch of new drugs. Firms headquartered in countries that regulate price reach fewer markets than those in countries without price controls. Companies avoid price-controlled markets, and are less likely to introduce products in additional markets after entering a price-controlled country. Launches into low-price European countries are further delayed following legalization of parallel imports. The results suggest that price regulation in one country affects entry into other countries, and may affect the strategies of domestic firms.

Plant shutdowns shape industry productivity, the dynamics of employment, and industrial restructuring. Plant closures account for more than half of gross job destruction in U.S. manufacturing. This paper examines the effects of firm structure on U.S. manufacturing plant closures. Plants belonging to multiplant firms and those owned by U.S. multinationals are less likely to exit. However, the superior survival chances are due to the characteristics of the plants rather than the nature of the firms. Controlling for plant and industry attributes, we find that plants owned by multiunit firms and U.S. multinationals are much more likely to close.

In this paper we develop and estimate a model to explain variations in immigration to the United States by source country since the early 1970s. The explanatory variables include ratios to the United States of source country income and education as well as relative inequality. In addition, we incorporate the stock of previous immigrants and a variety of variables representing different dimensions of the immigration quotas set by policy. We use the results to shed light on the impact of policy by simulating the effects of the key changes in immigration policy since the late 1970s. We also examine the factors that influenced the composition of U.S. immigration by source region over the entire period.

This paper examines the relationship between workforce demographics and aggregate productivity. Changes in the age structure of the workforce are found to be significantly correlated with changes in aggregate productivity. Different demographic structures may be related to almost one-quarter of the persistent productivity gap between the OECD and low-income nations as well as part of the productivity divergence between 1960 and 1990.