Colombia: 1964, 1973, 1993
Kenya: 1989, 1999
Mexico: 1960, 1970, 1990, 2000
United States: 1960, 1970, 1980, 1990

All persons.

BPLCNTRY indicates the person's country of birth.

The list of countries available in each census is different. The censuses that do not provide specific country of birth for foreign-born persons are not included in this variable, but foreign-born persons can be distinguished from native-born persons using the variable NATIVITY.

The first digit of BPLCNTRY corresponds to continents and the second to subcontinental regions. The first digit is fully comparable; the second is largely so. The third and fourth digits are to be read together and identify countries alphabetically by English name within subcontinents. The final digit, which is used sparingly, preserves detail for specific countries that was incompatible across samples.

Some countries get individual codes and others are grouped under the "not specified" ("n.s.") categories coded at the end of the numbering system for their region (codes ending in "999").

The "not specified" categories within each continent or subcontinent are relative to the country availability in each census, which can differ greatly.

With minor exceptions, BPLCNTRY follows the geographical groupings designed by the United Nations. Some places that get their own distinct country code in the UN system are (infrequently) coded together in IPUMS-International in order to increase compatibility across samples (e.g., Korea rather than North Korea and South Korea). The final digit of BPLCNTRY retains the full geographic information to distinguish among these combined categories within countries.

In addition to the differing availability of country codes, users should be aware of historical changes in the boundaries of countries and the creation of new countries over time. Essentially, users must ask themselves where a person who responded with a given country of birth would have been coded in a census, given the available categories specified in that sample.

1964 identifies substantially fewer countries than the more recent Colombian samples.

Both censuses are comparable, but offer very limited detail. Only select African countries get individual codes. Outside of Africa, persons are grouped by continent of birth.

The 1990 and 2000 censuses identify many more countries than the older Mexican samples do.

The 4-digit country code for the United States combines the U.S. proper and its outlying areas and territories. The fifth digit of BPLCNTRY distinguishes U.S. states from the territories. To enhance consistency with other countries, Puerto Rico is given its own Caribbean country code, rather than getting a code among the U.S. outlying areas and territories.

The U.S. system is very detailed. The residual categories for regions (the "n.s." categories) often differ from one another and may not precisely match the geographic bounds implied by the UN system that was adopted for IPUMS-International. In practice, however, this is a very minor inconsistency, because those residual categories are uniformly very small.

Some of the extremely small sub-country categories in the most recent U.S. samples have been combined with their parent country or residual categories. All these detailed codes are available in the IPUMS-USA database.