Age heaping among individuals in selected South Asian countries: evidence from Demographic and Health Surveys.

Age misreporting is a common phenomenon in Demographic and Health Surveys, and there are numerous reasons for this. The trend and pattern of disparity in age heaping vary between countries. The present study assesses age heaping in the selected South Asian countries of Afghanistan, India, Nepal, Bangladesh and Pakistan using data from the most recent round of the Demographic and Health Survey. The respondent sample sizes were 203,703 for Afghanistan, 2,869,043 for India, 49,064 for Nepal, 81,618 for Bangladesh and 100,868 for Pakistan. Age heaping was assessed by respondent's age, education level, sex and level of education. Whipple's index was calculated to assess systematic heaping on certain ages as a result of digit preference. Bangladesh, Afghanistan and India showed stronger preference for ages ending with the digits '0' and '5' compared with Pakistan and Nepal among uneducated respondents. On the other hand, strong avoidance of ages ending in the digits '1', '4' and '9' was observed in Bangladesh, Afghanistan and India. However, urban-rural place of residence was not found to be associated with digit preference in the study countries. Among males, age misreporting with the final digits '0' and '5' was highest in Bangladesh, followed by Afghanistan and India, and Nepal showed the least displacement. Strong digit preference and avoidance, and upper age displacement, were witnessed in the surveys conducted in Bangladesh, Afghanistan and India on the parameters of sex and education level. Innovative methods of data collection with the measurement and minimization of errors using statistical techniques should be used to ensure accuracy of age data.