The sociological study of state punishment policies and practices, long a minor criminological specialty, is currently undergoing change. Stimulated at least in part by the historically unprecedented growth in the U.S. prison population over the past 30 years, the study of prison populations and the reasons they change has attracted new researchers and has stimulated new theories. Punishment is no longer being considered in isolation from other social institutions. The relationships Beckett and Western find between penal and welfare policies and between imprisonment rates and race have now been found in several studies of U.S. imprisonment rates. Their analysis suggests prison populations can be predicted but their model is not nearly as successful in explaining changes in prison populations. Further, their analysis indicates the relationship between imprisonment and welfare policy has become stronger over time such that penal and welfare policies have increasingly clustered into coherent policy regimes. Downes discusses prison policies in the context of welfare, social control, economic influences, and globalization, and he contends the trend toward harsh penal policies in both the United States and Europe may be out of control. 65 references and 7 notes