ABSTRACT
Estimates of excess deaths have been widely used to measure the overall impact of the COVID-19 pandemic on mortality. We investigate the validity of a method-the later/earlier method- developed for forecasting the number of deaths one would expect if no shock occurred. We apply this method to estimate excess mortality during the first COVID-19 wave in France and Spain (February-June 2020), stratified by age, sex, and region. Although both countries recorded similar numbers of COVID-19 deaths, Spain had higher excess mortality. The results are informative about differences in COVID-19 vulnerability for population subgroups and spatial areas: adults aged 75-85 were the hardest hit;Ile-de-France (Paris region) in France and Comunidad de Madrid in Spain had the highest excess mortality. Applicable to other demographic phenomena, the later/earlier method is simple, requires fewer assumptions than other forecasting methods, and is less biased and more accurate than the 5-year-average method.