A global analysis of the effects of social security reforms on the retirement incentives and labor force trends of older workers. Employment among older men and women has increased dramatically in recent years, reversing a downward trend in the closing decades of the twentieth century. Social Security Programs and Retirement around the World examines how changing retirement incentives have reshaped labor force participation trends among older workers. The chapters feature country-specific analyses for Belgium, Canada, Denmark, France, Germany, Italy, Japan, Netherlands, Spain, Sweden, the United Kingdom, and the United States. They find that while there is significant heterogeneity across countries, the reforms of recent decades have generally reduced the implicit tax on work at older ages. These changes correlate positively with labor force participation. The studies exploit the variation in the timing and extent of reforms of retirement incentives and employ microeconometric methods to investigate whether this correlation reflects a causal relationship. Policy changes appear to have contributed to rising labor force activity, but other factors like the role of women in the labor force, improved health, and changes in private pensions likely also play important roles.