This paper looks at the relationship between the institutional design of the social security system and retirement from the labour force in three countries: Italy, Spain and the USA. Our works stresses the importance of dynamic incentives embedded in social security systems throughout the world and makes use of these three countries as an example. In fact they provide enough variability in their welfare programs that can be exploited to explain differences in retirement behavior. We show that social security rules are very important for individual's decisions to retire at a given age and that policy changes aimed at achieving age-neutrality of social security systems have a crucial role in shaping welfare.