and new—obtained from various disciplines, each with its own domain of interest and style of analyzing and presenting data. Some authors review research fields that use mature methodologies and standard approaches, while others report on new avenues of investigation that are in their infancies. In these latter cases, concepts, methods, and measures still need to be refined. Nevertheless, each of the papers in this volume conveys important ideas and information.
To better understand some of the main features of the diverging trends in life expectancy across countries, the paper by Glei, Meslé, and Vallin (Chapter 2) examines mortality changes and differences in 10 countries where high-quality mortality and cause of death data are available. In some of them, life expectancy has increased rapidly in recent years; in others, progress is lagging as in the United States.
By basing their analysis on a solid foundation of high-quality statistics, the authors are able to explore a number of important empirical relationships and see whether they stand up to close scrutiny. They point out that the story for male life expectancy at age 50 (e50) is somewhat different than the story for female life expectancy at age 50. For the 10 countries examined, U.S. males have consistently ranked among the lowest in terms of e50. Consequently, even though they currently appear to be faring relatively poorly, the relative position of U.S. males has not deteriorated over the last 50 years.
In contrast, the relative rank of U.S. females has deteriorated over the last 30 years. Around 1980, the pace of gains in life expectancy at age 50 slowed among women in the United States as it did for women in Denmark and the Netherlands; for the other countries, the pace of gains increased. Consequently, over the last quarter-century, gains in e50 among U.S. women (2.4 years) were about half those in Australia, France, and Italy (4.5-5.2 years) and less than 40 percent of that of Japan (6.3). The authors identify similar important empirical relationships by examining the contributions to gains in e50 by age and sex over time.
The authors provide a careful examination of cause-of-death statistics for those countries for which detailed data are available. The purpose of the analysis is to identify particular causes of death that can explain the relatively poor performance in gains in e50 for the three countries with the least amount of progress, Denmark, the Netherlands, and the United States. Comparative analysis of cause of death is complicated by issues of variation in coding practices across countries and over time. Nevertheless, the authors are partly successful in being able to identify particular causes of death that are either contributing factors or that can be ruled out. And