Book excerpt: In 1950 men and women in the United States had a combined life expectancy of 68.9 years, the 12th highest life expectancy at birth in the world. Today, life expectancy is up to 79.2 years, yet the country is now 28th on the list, behind the United Kingdom, Korea, Canada, and France, among others. The United States does have higher rates of infant mortality and violent deaths than in other developed countries, but these factors do not fully account for the country's relatively poor ranking in life expectancy. International Differences in Mortality at Older Ages: Dimensions and Sources examines patterns in international differences in life expectancy above age 50 and assesses the evidence and arguments that have been advanced to explain the poor position of the United States relative to other countries. The papers in this deeply researched volume identify gaps in measurement, data, theory, and research design and pinpoint areas for future high-priority research in this area. In addition to examining the differences in mortality around the world, the papers in International Differences in Mortality at Older Ages look at health factors and life-style choices commonly believed to contribute to the observed international differences in life expectancy. They also identify strategic opportunities for health-related interventions. This book offers a wide variety of disciplinary and scholarly perspectives to the study of mortality, and it offers in-depth analyses that can serve health professionals, policy makers, statisticians, and researchers.