Age and Birth Date Reporting in Thailand: Evidence from the 1987 Demographic and Health Survey
Chayovan, Napaporn, and John E. Knodel. "Age and Birth Date Reporting in Thailand: Evidence from the 1987 Demographic and Health Survey." PSC Research Report No. 91-215. 4 1991.
This study examines age and birth date reporting in Thailand based on the 1987 Thailand Demographic and Health Survey. Findings serve as a useful example of how age and birth date reporting are more complex phenomena than might be suspected initially, even in a society where age and birth dates are relatively well known. Results are presented in three main sections. First, the authors examine several aspects of birth date reporting by reproductive aged ever-married women for themselves and for their children. Second, they examine aggregate age reporting patterns, focusing on the extent of age heaping for all household members as well as for ever-married women and their children. Third, stated ages and ages as calculated from birth dates are compared directly at the level of the individual for ever-married women respondents themselves and their living children.
Findings show that most Thais have a reasonably accurate idea of their own age. However, because of the practice of equating one's age simply with the difference between the current year and the year of birth, ages are not necessarily reported in terms of completed years. Studies which take place early in the calendar year are quite susceptible to this form of misreporting. The reporting of the ages of older children follow this same pattern. The reporting of younger children's ages is often in units of less than whole years. This practice declines rapidly with the age of the child. A consequence of this is that the proportion of infants who are actually under one year old (in terms of completed age) but who are reported as age one is smaller than the proportion of children who in fact are age one but are reported as age two, and so on until the age at which children's ages are no longer reported in greater detail than whole years. The study calls for further research in the area of age reporting in specific cultural contexts.