Colombia: 1964, 1973, 1985, 1993
France: 1962, 1968, 1975, 1982, 1990
Kenya: 1989, 1999
Mexico: 1960, 1970, 1990, 2000
United States: 1960, 1970, 1980, 1990
Vietnam: 1989, 1999

All persons.

AGE gives age in years as of the person's last birthday prior to or on the day of enumeration. Note: Some samples provide additional age variables, such as year of birth or age in months for the very young.

AGE is fully comparable for all samples except 1962 France. For 1962 France, age since last birthday was inferred from an alternative age variable: age that the person would achieve in calendar year 1962.

Age is top-coded differently among the various samples.

The 1962 French sample gives only the age that the person would achieve in calendar year 1962. We have inferred age since last birthday by randomly assigning persons to birth months and adjusting the age relative to the date the census was taken. The original age as it was reported in the sample is preserved in another variable.

The French censuses asked for exact date of birth on the forms. Age was calculated from these responses by the creators of the French samples. The exact dates are not available in the microdata.

The Kenyan census instructions show considerable concern about improper age reporting, going so far as to provide enumerators with various strategies and a calendar of regional historical events to prompt more accurate age estimates from respondents.

Some ages in the 1960 sample were clearly erroneous; we have coded all values over 125 as missing.

The 1989 census asked for month and year of birth on the forms. Exact age in years was calculated from these responses relative to April 1, the day of the census.