We evaluate the performance of alternative test statistics in event studies which include NASDAQ daily security returns. We document varying degrees of test statistic misspecification in NASDAQ samples. In particular, we find that the commonly used standardized test statistic is misspecified in most settings. Although less pervasive, misspecification is also evident in the portfolio test statistic estimated using the time series of portfolio mean abnormal returns. The nonparametric rank statistic [introduced in Corrado (1989)] performs the best overall in NASDAQ samples; we recommend its use with market model abnormal returns based on an equal-weighted NASDAQ market index.

This paper examines optimal monetary policy under uncertainty in a context in which policymakers are able to make credible policy commitments. The authors study an optimal taxation problem of minimizing the social cost of financing a stochastic and exogenous level of government transfers. Since, in the basic model, the welfare costs of inflation derive only from expected inflation, the optimal monetary policy is highly responsive to the state of nature. In a benchmark case in which all shocks are transitory, the optimal policy calls for loading all the variability of government transfers on the shoulders of the inflation tax. Copyright 1993 by The Review of Economic Studies Limited.

This article uses very detailed information on graduates of the University of Michigan Law School to examine male-female pay differences in that population. Men and women in this population have virtually identical human capital on graduation from law school, allowing us to examine carefully the different impact of children and work history on men's and women's careers and earnings. Taking time from work in order to care for children reduces wages significantly, but a rich set of controls, including childcare, work history, school performance, and job setting measures, still leave one-fourth to one-third of the earnings gap unexplained.

Reporting lags, Squared market model prediction errors, Information content, SEC Filings

Sourcing, Make-or-Buy decisions, Product quality, Unverifiable information

[We investigate predictability in national equity market returns, and its relation to global economic risks. We show how to consistently estimate the fraction of the predictable variation that is captured by an asset pricing model for the expected returns. We use a model in which conditional betas of the national equity markets depend on local information variables, while global risk premia depend on global variables. We examine single- and multiple-beta models, using monthly data for 1970 to 1989. The models capture much of the predictability for many countries. Most of this is related to time variation in the global risk premia.]

The authors study the problem of optimal taxation in three infinite-horizon, representative-agent endogenous growth models. The first model is a convex model in which physical and human capital are perfectly symmetric. The authors' second model incorporates elastic labor supply through a Lucas-style technology. Analysis of these two models points out the danger of assuming that government expenditures are exogenous. In their third model, the authors include government expenditures as a productive input in capital formation, showing that the limiting tax rate on capital is no longer zero. In numerical simulations, they find similar effects on growth and welfare in all three models. Copyright 1993 by University of Chicago Press.

We study the problem of optimal taxation in three infinite-horizon, representative-agent endogenous growth models. The first model is a convex model in which physical and human capital are perfectly symmetric. Our second model incorporates elastic labor supply through a Lucas-style technology. Analysis of these two models points out the danger of assuming that government expenditures are exogenous. In our third model, we include government expenditures as a productive input in capital formation, showing that the limiting tax rate on capital is no longer zero. In numerical simulations, we find similar effects on growth and welfare in all three models.