Mortality Crossovers: Reality or Bad Data?

The number of centenarians in Brazil: Indirect estimates based on death certificates

“…However, we remain skeptical about the population counts reported by the Brazilian census bureau. At older ages, data are beset with a variety of problems in many populations (Coale and Kisker 1986, Kannisto 1988, Coale and Caselli 1990, Preston, Elo, and Stewart 1999, Thatcher, Kannisto, and Andreev 2002, and there is no reason to believe these errors are absent or less frequent in Brazil. Indeed, a simple inspection of the ratio of the population aged 100 and older to 85 reveals notable discrepancies between Brazil and other selected countries of presumably higher quality data (Table 1).…”

Exceptional Longevity in Okinawa:

“…According to Coale and Kisker (1986) this crossover could result from a selection effect or bad data. We think that both could apply to the findings for Okinawa.…”

“…Figure 13 shows the mortality crossover for the 2000 life table; the mortality rates for Okinawa are higher before and lower after age 60, relative to Japan. Coale and Kisker (1986) made an in-depth study of the possible reasons for mortality crossovers. The two main explanations are (i) a selection effect and (ii) age misreporting or bad data.…”

The quality of demographic data on older Africans

“…Coale and Kisker showed for a number of populations that age misreporting at older ages generated misleading mortality rates (Coale and Kisker 1986). Poor age reporting in many Sub-Saharan African populations has implications for the interpretation of a number of development-related indices, such as the dependency ratio.…”