Heterogeneity and Intermarriage
利用1970年美国人口普查数据，验证了群体规模与族外通婚率负相关、区域异质性与通婚率正相关的理论，并发现种族异质性因经济差距而例外。
public use sample of the 1970 U.S. Census. The two theoretical predictions are: (1) a group's relative size is inversely related to the proportion of its members who are outmarried; and (2) an SMSA's heterogeneity is directly related to the rate of intermarriage in it. The underlying assumption is that the structural constraints of size distributions affect marriage notwithstanding cultural values promoting ingroup marriages. The data confirm the two predictions (corroborating the underlying assumption) for most size differences and most forms of heterogeneity examined. Thus, heterogeneity in national origins, mother tongue, birth region, industry, and occupation raise intermarriage rates in these respects. Although racial heterogeneity does not have this predicted effect, the reason is that the great socioeconomic differences between races consolidate racial boundaries and thereby counteract the influence of heterogeneity on intermarriage. Empirical evidence supports this explanation: when racial income differences are controlled, the predicted positive relationship between racial heterogeneity and intermarriage becomes apparent.