This book analyzes the productivity theory of pensions. First, it reviews the history and institutional practices of private pensions and government policy. Chapter 1 discusses demand-side and supply-side perspectives on pensions, the significance of the productivity theory of pensions, and the organization of this book. Chapter 2 traces origins of private pensions and evolution of current coverage and discusses federal policies. Chapter 3 shows how workers who leave a job with a defined-benefit pension are penalized, presents advantages of defined-benefit plans in establishing retirement incentives, and discusses how defined-contribution plans may convey productive incentives. Second, the book considers whether pension incentives are consistent with models of internal labor markets. Chapter 4 reviews employment models in which specific training and monitoring costs generate job-specific productivity gains and compares pension incentives with ideal solutions. Third, the book evaluates empirical evidence that pensions promote productivity. Chapter 5 reviews empirical studies that test the pension-productivity hypothesis, which addresses the growing popularity of defined-contribution plans. It considers whether the declining market share of defined-benefit plans is evidence that pension incentives are no longer important. Chapter 6 tests one of the channels by which pensions may enhance worker productivity: by promoting investments in worker training. Chapter 7 reports direct estimates of productivity gains for firms that sponsor defined-benefit pensions. Chapter 8 presents a pension policy and research recommendations. (Appendixes contain 131 references and author and subject indexes.) (YLB)