Comparative analysis of poverty dynamics—incidence, transitions, and persistence—can yield important insights about the nature of poverty and the effectiveness of alternative policy responses. This manuscript compares poverty dynamics in four advanced industrial countries (Canada, unified Germany, Great Britain, and the United States) for overlapping six-year periods in the 1990s. The data indicate that poverty persistence is higher in North America than in Europe; for example, despite high incidence, poverty in Great Britain is relatively transitory. Most poverty transitions, and the prevalence of chronic poverty, are associated with employment instability and family dissolution in all four countries. The results also suggest that differences in social policy are crucial for the observed differences in poverty incidence and persistence between Europe and North America.