Drawing on evidence from the European Union (with comparisons to other industrialized countries including the United States and Canada), the authors demonstrate that the effective retirement age is influenced by social security regulations (such as a change in eligibility age) and discuss ways of measuring these embedded incentives. Fenge and Pestieau examine the implicit taxes on prolonged working life from normative and political economy perspectives. They discuss optimal payroll tax rates that minimize distortions of labor supply and retirement decisions and consider alternative ways to finance benefits, including consumption and capital income taxation. They discuss why policies are designed to discourage employment among older workers and why reforms to counter this often meet resistance. They demonstrate, contrary to the belief of many European governments, that pushing older workers into retirement does not free jobs for young unemployed workers.