Mexico: 1970, 2000
United States: 1960, 1970, 1980, 1990

Mexico 1970: Persons age 12+.
Mexico 2000: All persons.
United States 1960-1970: Persons age 14+.
United States 1980: Persons age 15+.
United States 1990: All persons.

INCTOT reports the person's total personal income from all sources for the previous calendar year (U.S.) or month (Mexico).

Amounts are expressed as they were reported at the time of the census in the currency of the respective country (dollars for the United States, pesos for Mexico). Figures are not adjusted for inflation or devaluation.

Figures for some samples represent the midpoints of intervals and are not exact currency amounts.

Mexico underwent major devaluations of the currency in the 1970s, 1980s, and 1990s. A "new" peso equivalent to one thousand old pesos was introduced in 1993. Users must account for these changes when making comparisons across this period.

Income in the 1970 sample was reported in eighty categories, each representing a range of incomes. The data have been recoded to the midpoints of the intervals to make them more comparable with other samples.

All censuses told respondents to include income from all sources, with the later censuses giving more detailed instructions.

The codes for all years prior to 1990 represent midpoints of intervals and are not exact dollar amounts.

Persons in the U.S. samples can report negative incomes. The data in each sample are top-coded: $25,000 in 1960, $50,000 in 1970, and $75,000 in 1980. In 1990, incomes higher than $400,000 are reported as the state median of all values over $400,000 in that year.