Knowledge that Transforms

Econometric analyses of treatment response commonly use instrumental variable (IV) assumptions to identify treatment effects. Yet the credibility of IV assumptions is often a matter of considerable disagreement. There is therefore good reason to consider weaker but more credible assumptions. To this end, we introduce monotone instrumental variable (MIV) assumptions and the important special case of monotone treatment selection (MTS). We study the identifying power of MIV assumptions alone and combined with the assumption of monotone treatment response (MTR). We present an empirical application using the MTS and MTR assumptions to place upper bounds on the returns to schooling

In this article, I evaluate the hypothesis that firms respond to negative demand shocks by assigning workers to tasks that require less skill than the tasks they normally carry out. Using changes in employment in state‐industry cells as a measure of demand conditions facing individual firms, I provide evidence in favor of the hypothesis. Furthermore, the skill requirements of the tasks carried out by workers are procyclical. The results are consistent with a specific capital model where employers move workers between tasks so that layoffs are concentrated on workers with low levels of firm‐specific human capital.

Differences in test scores of white and black students have narrowed substantially over time, falling by one‐half since 1970s. Some have speculated that this convergence is due to changes in family background or convergence in school quality. In this article we decompose the convergence in test scores into that portion due to changes in parental education, changes in school quality, and a narrowing of the within‐school gap in test scores. Only about 25% of the overall convergence is attributable to changing family and school characteristics. We find that nearly 75% of the convergence is attributable to changes within schools.

Although the debate over Affirmative Action is both high-profile and high-intensity, neither side's position is based on a well-established set of research findings. Economics provides an extensive, wellknown literature on which to draw regarding the existence and extent of labor market discrimination against women and minorities, although views may often conflict, and a less extensive but also well-known literature on the effects of Affirmative Action on the employment of women or minorities. However, research by economists provides much less evidence and even less of a consensus on the question of whether Affirmative Action improves or impedes efficiency or performance, which is perhaps the key economic issue in the debate over Affirmative Action. This review focuses on all of these issues regarding Affirmative Action, but the major focus is on the efficiency/performance question.

This paper reviews research that uses longitudinal microdata to document productivity movements and to examine factors behind productivity growth. The research explores the dispersion of productivity across firms and establishments, the persistence of productivity differentials, the consequences of entry and exit, and the contribution of resource reallocation across firms to aggregate productivity growth. The research also reveals important factors correlated with productivity growth, such as managerial ability, technology use, human capital, and regulation. The more advanced literature in the field has begun to address the more difficult questions of the causality between these factors and productivity growth.

This paper uses principal-agent theory to examine the optimal mix of monetary- and resource-based penalties in two institutional settings: a market economy and a centrally planned economy. In a centrally planned economy, an agent's wealth depends mostly on real resources and little on monetary resources; therefore, monetary-based penalties have less penalizing power than do resource-based penalties. Based on this premise, theory generates hypotheses regarding differences in the optimal mix of penalty types between the two economic systems. This paper empirically tests these hypotheses using data from the Czech Republic regarding enforcement responses to water-damaging accidents (such as oil spills).

This paper analyzes the properties of a number of estimators that can be used to estimate short-run persistence in mutual fund returns. When data for different funds are pooled, it is advisable to correct for cross-sectional differences in expected returns. However, these adjustments may induce biases in the estimated persistence coefficients and thus lead to spurious persistence. Theoretical derivations, combined with a Monte Carlo study, show that these biases cannot be neglected for the samples that are typically used in applied work. We also estimate the short-run persistence in two samples of U.S. open-end mutual funds using quarterly returns for 1987–1994. An important conclusion is that the results are quite sensitive to the estimation method that is employed.

This paper examines how assumptions imposed on the data influence estimates of schooling's effect on earnings. The paper models schooling decisions as treatment effects and imposes assumptions about schooling selection to estimate bounds on the treatment effect. The study begins by using the worst-case bounds derived by Manski (1989, 1990, 1994, 1995) and adds assumptions from the Roy model of schooling self-selection to narrow the bounds on the schooling treatment effect. The bounds are narrowed further by using family structure, college proximity, and school-quality characteristics as exclusion restrictions. The selection problem requires the researcher to make explicit assumptions to estimate the effect of schooling on earnings. This paper demonstrates that different selection assumptions yield very different results.

This paper studies the effect of corruption on foreign direct investment. The sample covers bilateral investment from twelve source countries to 45 host countries. There are two central findings. First, a rise in either the tax rate on multinational firms or the corruption level in a host country reduces inward foreign direct investment (FDI). In a benchmark estimation, an increase in the corruption level from that of Singapore to that of Mexico would have the same negative effect on inward FDI as raising the tax rate by fifty percentage points. Second, American investors are averse to corruption in host countries, but not necessarily more so than average OECD investors, in spite of the U.S. Foreign Corrupt Practices Act of 1977.

This paper provides a descriptive analysis of the long- and short-run correlations among saving, investment, and growth rates for 123 countries over the period 1961-94. Three results are robust across data sets and estimation methods: i) lagges saving rates are positively related to investment rates; ii) investment rates Granger cause growth rates with a negative sign; iii) growth rates Granger-cause investment with a positive sign.