Age misreporting in censuses in developing countries: a record linkage study in health and demographic surveillance systems in Senegal

Bruno Masquelier, Université Catholique de Louvain
Gilles Pison, French National Museum of Natural History and Institut National d'Études Démographiques (INED)
Cheikh Tidiane Ndiaye, Agence Nationale de la Statistique et de la Démographie (ANSD)
Lucie Lecomte, Institut de Recherche pour le Développement (IRD)
Ndèye Binta Diémé, Agence Nationale de la Statistique et de la Démographie (ANSD)
Ibrahima Diouf, Agence Nationale de la Statistique et de la Démographie (ANSD)
Valérie Delaunay, Institut de Recherche pour le Développement (IRD)

Ages reported in censuses in developing countries are subject to errors and bias resulting in uncertainties in population estimates and age distributions. We examine these biases in the case of the last two censuses of Senegal, conducted in 2002 and 2013, by matching at the individual level the information they collected with those held by the health and demographic surveillance systems in place since three decades in rural Senegal. The information on the ages held by these systems is of high quality and serves as a reference to examine the quality of the ages reported in the censuses. We quantify the differences between reported and actual ages, check if the errors and bias have been reduced or not between the 2002 census and that of 2013, and examine the consequences of age misreporting on demographic estimates in the studied populations.