1990, foreign-born and native-born whites had similar intermarriage rates. The rates for Asians and Hispanics, however, were higher for the native-born than for the foreign-born. For blacks, intermarriage rates are lower for the native-born.

Whether one is of single or multiple-ancestry also matters. Intermarriage rates are higher for persons of all racial/ethnic groups who themselves report multiple-ancestries, including a racial/ethnic identification that is different from the primary one. There is considerable variation, however, in intermarriage rates for persons of multiple-ancestry compared with those of single ancestry.16

To calculate estimates of exogamy by generation, we note that earlier work with 1970 census and survey data, mostly analyzing Hispanics, revealed a roughly linear increase in intermarriage rates for the first, second, and third generations (Gurak and Fitzpatrick, 1982). If we take the native-born population as an estimate for the second-plus generations and locate the estimate appropriate for the generational composition of racial/ethnic groups in 1990, then the native-born estimates for the white and black populations reflect primarily the third and later generations. We use the native-born information as an estimate for the third and fourth generations and estimate the second generation by averaging estimates for the first and third generations.

The native-born estimate for the Asian population is for a population centered on about the 2.6th generation. We assume that the fourth-plus generation is the same as the third. For the Hispanic population, we center the native-born population at 2.5.

Data on exogamy are available from several sources for the U.S. population. Although some data on intermarriage are available, data on intergroup nonmarital unions are not. We can approach exogamy using what is known about intermarriage, recognizing that information on currently married-couples differs from data on births to parents of different racial/ethnic origins. For these population projections, we rely on data from the 1990 census on intermarriage rates for the foreign- and the native-born. For the native-born, we assume that the generational pattern for the second and third-plus generations, for each racial/ethnic group, was simi


rately for the foreign-born and the native-born. For example, the intermarriage rate for foreign-born whites is 2.4 for single ancestry and 2.7 for all ancestries. We assume that the ratio of the two, 0.89, offers an estimate for adjusting the exogamy rate of 1 1.7. Thus, we derive the estimate of 0.89 x 1 1.7, or 10.4 percent exogamy for the foreign-born white population.


Data on intermarriages by race/ethnicity in decennial censuses measure existing marriages. Although the flow of new marriages affects the stock of existing marriages, such effects lag shifts in new intermarriage patterns by several decades. This lag has implications for population projections, which rely on assumptions about the intermarriage levels for modeling fertility. Ideally, we would prefer estimates on the race/ethnicity of new marriages. Intermarriage data from the census have a handicap for population projections: a significant proportion of births occurs to persons or couples who are not married. We use special tabulations from the National Center for Health Statistics based on complete birth registration data for 1994.

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