This article presents evidence that turnover is negatively selective on a worker's job performance. At establishments with about seventeen employees, workers who are one standard deviation (21 percent) less productive than average during the first few months on the job are 11 percentage points more likely to be laid off or fired and 7 percentage points more likely to quit during the succeeding year. At large nonunion establishments and in small labor markets, productivity has large effects on involuntary separations, but almost no effect on quits. Productivity appears to be positively related to layoffs and quits at unionized establishments.

Our review of the evidence suggests that the claims of the advocates of standards and examination based reform of American secondary education may be right. The countries and Canadian provinces with such systems outperform other countries at comparable levels of development. In addition, New York State, the only state with a CBEEE, does remarkably well on the SAT test when student demography is held constant (Bishop 1996). CBEEEs are not, however, the most important determinant of achievement levels. CBEEEs are common in developing nations where achievement levels are often quite low [eg. Columbia and Iran]. Belgium, by contrast, has a top quality education system without having a CBEEE. More research on the effects of CBEEEs is clearly in order.