Estimating age-specific mortality using calibrated splines

Demographers have developed a number of methods for expanding abridged mortality data into a complete schedule; however, these can be usefully applied only under certain conditions, and the presence or absence of one or more additional sources of incompleteness can degrade their relative accuracy, lead to implausible profiles, or even cause the methods to fail. We develop a new method for expanding an abridged schedule based on calibrated splines; this method is accurate and robust in the presence of errors in mortality rates, missing values, and truncation. We compare its performance with the performance of existing methods for expanding abridged data and find that it is superior to current methods at producing accurate and plausible complete schedules over a broad range of data-quality conditions. The method when applied is a valuable addition to existing tools for estimating mortality, especially for small nations, countries with incomplete vital statistics, and subnational populations.