The Survivor Ratio Method for Estimating Numbers at High Ages

Only a few countries have official population statistics which are sufficiently accurate to produce reliable estimates of death rates at high ages. For other countries, there are several methods which can be used to produce improved estimates. The choice is important for research on old age mortality. In 1999 the Max Planck Institute for Demographic Research undertook a research project to compare the performance of the three leading methods, using data for nine countries over 35 years. This paper describes the research and the results, which were unexpectedly simple. It also gives an authoritative account of the most successful method.