The probit is generally considered to be one of the easiest nonlinear maximum likelihood problems. Nonetheless, in the course of at-tempting to replicate G. S. Maddala’s (1992, pp. 335–38) probit example, Houston Stokes (2003) encountered great difficulty. Of the six coeffi-cients, five coefficients/standard errors he could duplicate, but the sixth was off by more than rounding error. So he tried another package. And another. And another.... Finally, five dif-ferent packages had declared convergence to five solutions that differed only in the sixth coefficient. Estimates of the sixth coefficient ranged from 4.4 to 8.1, and estimates on its standard error ranged from 46 to 114,550.

An Examination of the Influence of Theory and Individual Theorists on Empirical Research in Microeconomics by Pierre-André Chiappori and Steven D. Levitt. Published in volume 93, issue 2, pages 151-155 of American Economic Review, May 2003

Many households received income tax rebates in 2001 of $300 or $600. These rebates represented advance payments of the tax cut from the new 10 percent tax bracket. Based on a survey of a representative sample of households, this paper finds that only 22 percent of households receiving the rebate would spent it. Instead, they would either save it or use it to pay off debt. This very low rate of spending represents a striking break with past behavior, which would have suggested a much higher rate of spending. The low spending rate implies that the tax rebate provided a very limited stimulus to aggregate demand.

Returns to Education: Evidence from U.K. Twins by Dorothe Bonjour, Lynn F. Cherkas, Jonathan E. Haskel, Denise D. Hawkes and Tim D. Spector. Published in volume 93, issue 5, pages 1799-1812 of American Economic Review, December 2003

The Effects of Environmental Regulation on Technology Diffusion: The Case of Chlorine Manufacturing by Lori D. Snyder, Nolan H. Miller and Robert N. Stavins. Published in volume 93, issue 2, pages 431-435 of American Economic Review, May 2003

The Future of the IMF and World Bank: Panel Discussion by Stanley Fischer, Allan H. Meltzer, Jeffrey D. Sachs and Nicholas Stern. Published in volume 93, issue 2, pages 45-50 of American Economic Review, May 2003

This paper investigates the role of seasonal affective disorder (SAD) in the seasonal time-variation of stock market returns. SAD is an extensively documented medical condition whereby the shortness of the days in fall and winter leads to depression for many people. Experimental research in psychology and economics indicates that depression, in turn, causes heightened risk aversion. Building on these links between the length of day, depression, and risk aversion, we provide international evidence that stock market returns vary seasonally with the length of the day, a result we call the SAD effect. Using data from numerous stock exchanges and controlling for well-known market seasonals as well as other environmental factors, stock returns are shown to be significantly related to the amount of daylight through the fall and winter. Patterns at different latitudes and in both hemispheres provide compelling evidence of a link between seasonal depression and seasonal variation in stock returns: Higher latitude markets show more pronounced SAD effects and results in the Southern Hemisphere are six months out of phase, as are the seasons. Overall, the economic magnitude of the SAD effect is large.

The Role of the Family in Immigrants' Labor-Market Activity: An Evaluation of Alternative Explanations: Comment by Francine D. Blau, Lawrence M. Kahn, Joan Y. Moriarty and Andre Portela Souza. Published in volume 93, issue 1, pages 429-447 of American Economic Review, March 2003