In many policy areas it is essential to use the best estimates of life expectancy, but it is vital to most areas of pension policy. This paper presents the conceptual differences between static period and dynamic cohort mortality tables, estimates the differences in life expectancy for Portugal and Spain, and compares official estimates of both life expectancy estimates for Australia, the United Kingdom, and the United States for 1981, 2010, and 2060. These comparisons reveal major differences between period and cohort life expectancy in and between countries and across years. The implications of using wrong estimates for pension policy, including financial sustainability, are explored.
