Comparability — Armenia [top]

The 2011 sample begins recording information from the year 1915 or earlier. The question was asked to all persons

Comparability — Burkina Faso [top]

In 1996 sample, large numbers of respondents are coded to "unknown" because they provided their age in years rather than the full date of birth. In 2006, the respondents provided their date of birth, if known.

Comparability — Cameroon [top]

In 1976, large numbers of respondents are coded to "unknown" because they provided their age at last birthday rather than the full date of birth. The 1987 sample only provides the age of the respondents.

Comparability — Cuba [top]

In 2012, the census begins recording information from year 1908 or earlier.

Comparability — Côte d'Ivoire [top]

In 1998, the sample begins recoding information from the year 1915 or earlier.

Comparability — Egypt [top]

Large numbers of respondents are coded to "unknown" because they provided their age rather than date of birth.

Comparability — Fiji [top]

In the 1966, 1976 and 1986 samples, the year of birth was estimated by the statistical office, if date of birth was unknown. The 2014 sample begins recording information from the year 1926 or earlier.

Comparability — France [top]

The unharmonized variables in the 1962, 1968, 1975, 1982, and 1990 samples collect the respondent's age in calendar year.

The 2006 sample from France combines data for the 2004-2008 years. Therefore, this sample includes births up to 2008.

In 2011 census begins recording information from year 1900 or earlier.

Comparability — Germany [top]

This variable is not available for the 1971 and 1981 samples. The variable is comparable in the remaining two samples.

Comparability — Guinea [top]

In the 1996 sample, over 70 percent of cases have no response. The 1996 sample starts recording information from year 1900 or earlier, while the 2014 sample starts at 1917 or earlier.

Comparability — Indonesia [top]

In the 1976 sample, approximately 31 percent of respondents did not report a birth year. However, these same respondents reported information on their age. It is possible that the enumerator recorded the age of the respondent but not his/her year of birth. These cases are located in the "Unknown" category of BIRTHYR.
Roughly half of respondents have no response in the 1980 sample.

Comparability — Iran [top]

In both 2006 and 2011, year of birth was reported according to the Hijiri (i.e., Persian) calendar. The Hijiri year was matched with the Gregorian year in which it began. For example, the year 1286 of the Hijiri calendar corresponds to a 12-month period that falls between 1907 and 1908 of the Gregorian calendar. Therefore, 1286 corresponds to 1907 in the harmonized variable.

See the unharmonized source variables to recover the information in both the Hijiri and Gregorian calendars.

Comparability — Israel [top]

The 2008 sample begins recording information from the year 1923 or before.

Comparability — Jamaica [top]

This variable is not available for the 1982 sample. The 1991 sample has an unknown category, while the 2001 sample does not.

Comparability — Mali [top]

The 2009 sample begins recording information from the year 1909.

Comparability — Morocco [top]

In the 1994 sample, responses based on the Hegira calendar are converted to the Gregorian calendar. Approximately 62% of respondents in this sample have no response.

Comparability — Nicaragua [top]

The 1995 and 2005 samples are comparable.

Comparability — Senegal [top]

The 2002 sample begins recording information from 1910 or before, while the 2013 sample starts from the year 1912 or before.

Comparability — South Africa [top]

In 2007 the census question was not asked of persons in institutions. In 2011 and 2016, the census questions was asked to all persons.

The census begins recording information from year 1900 or earlier in 2011 and 1908 or before in 2016.

Comparability — Spain [top]

The 2011 sample begins recording information from the year 1905.

Comparability — Thailand [top]

In the 2000 sample, the year was recorded according to the Thai Buddhist calendar and translated into the Western calendar.

A considerable proportion of respondents in all three samples reported their year of birth using the Thai Zodiacal calendar (12 animals). Because of the cyclical nature of this system and the imperfect correspondence between the Buddhist and the Western New Year date, IPUMS does not infer the year of birth in these cases. They are coded to the "unknown" category. See the unharmonized source variables to recover this information.

Comparability — Togo [top]

The 2010 sample begins recording information from the year 1912 or earlier.

Comparability — Uganda [top]

The 2002 sample begins recording information from 1905, while the 2014 sample starts from the year 1919.

Comparability — Ukraine [top]

The 2001 sample begins recording information from the year 1910.

Comparability — Uruguay [top]

The 2011 sample begins recording information from the year 1911.

Comparability — Vietnam [top]

The 1989 and 2009 samples have an unknown category, while the 1999 and 2019 samples do not. The 1999 sample begins recoding information from the year 1893 or earlier, while the 2019 from 1909 or earlier.