Social Security in the United States and in Europe is at a critical juncture. Through essays assembled in "Social Security Pension Reform in Europe", Martin Feldstein and Horst Siebert, along with a number of distinguished contributors, discuss the challenges facing Social Security reform in the aging societies of Europe. A remarkable range of European nations - Germany, France, Finland, the Netherlands, Poland, Romania, Italy, Sweden, the United Kingdom and Hungary - have implemented or are about to implement mixed Social Security systems that combine a traditional defined benefit of the pay-as-you-go system with an individual retirement account defined contribution of a capital-funded system. The essays here highlight the problems that the European pension reform process faces and how it differs from that of the United States. This timely volume should significantly enrich the debate on pension reform worldwide.