The International Social Security (ISS) project compares the experiences of a dozen developed countries to study Social Security Programs and Retirement Around the World. The project was launched in the mid 1990s and was motivated by decades of decline in the labor force participation rate of older men. The first phases of the project documented that social security program provisions can create powerful incentives for retirement that are strongly correlated with the labor force behavior of older workers. Since then, the dramatic decline in men’s labor force participation has been replaced by sharply rising participation rates. Older women’s participation has increased dramatically as well.