Inconsistencies in reports on siblings and children in survey data used to estimate mortality

In countries where the registration of deaths remains incomplete, the main sources of data on mortality are retrospective reports collected on the survival of close relatives. Birth and sibling histories are known to be plagued by recall errors but few methods exist to detect these errors. This paper introduces two simple approaches to assess the consistency between sibling histories and reports on the fertility of the previous generation. A comparison between the average size of sibships and the mean number of children ever born (CEB) to women of the previous generation indicates that a large proportion of siblings is omitted in Demographic and Health Surveys. On average the reported sibsizes are about 15 percent lower than expected from data on CEB. Discrepancies between reported and expected sibsizes are larger in sub-Saharan Africa than in other regions and they increase with the age of respondents. Second, a linkage of sibling histories reported by young women aged 15-18 with birth histories of their mothers when they live in the same household highlights frequent inconsistencies between mother's and daughter's reports on members of the same family. Daughters tend to report fewer siblings than expected from their mother's birth history, but more adult deaths.