This article examines the relationship between two methods for detecting group effects in nonexperimental data: covariance analysis and contextual analysts. The examination shows that contextual effects are a special case of the group effect obtained in covariance analysis. This finding implies...

This article uses Monte Carlo computer simulation to assess two alternative ways to control for population size in regression analysis. Contrary to the claim of some social scientists, regression analyses that use ratio variables to control for size (the “ratio method†of control) are...

Why is there greater variability in individual longevity in some populations than in others? We propose a decomposition method designed to address that question by quantifying the effects of population differences in the spread, allocation, and timing of the principal causes of death. Applying...

<Para ID="Par1">Lifespans are both shorter and more variable for blacks than for whites in the United States. Because their lifespans are more variable, there is greater inequality in length of life—and thus greater uncertainty about the future—among blacks. This study is the first to decompose the...</para>