Editing Social exchange theory (section)

===Interracial marriage===
Patterns of [[interracial marriage]] have been explained using social exchange theory. Kalmijn<ref name="Kalmijn">{{cite journal |jstor=2580162 |doi=10.1093/sf/72.1.119|title=Trends in Black/White Intermarriage|journal=Social Forces|volume=72|issue=1|pages=119–146|year=1993|last1=Kalmijn|first1=M.}}</ref> suggests that ethnic status is offset against educational or financial resources. This process has been used to explain why there are more marriages between black men and white women than between white men and black women. This asymmetry in marriage patterns has been used to support the idea of a racial hierarchy. Lewis,<ref name="Lewis">{{cite journal |pmid=22347504 |pmc=3276508|bibcode=2012PLoSO...731703L|title=A Facial Attractiveness Account of Gender Asymmetries in Interracial Marriage|journal=PLOS ONE|volume=7|issue=2|pages=31703|last1=Lewis|first1=Michael B.|year=2012|doi=10.1371/journal.pone.0031703|doi-access=free}}</ref> however, explains that the same patterns of marriage can be accounted for in terms of simple facial attractiveness patterns of the different gender by race groupings. Recent changes have seen an increase in black women marrying white men and a decrease in raw prevalence of interracial marriages when it comes to black women. There has also been a shift in the concentration of interracial marriage from mostly being between those with low education levels to those with higher levels of education.<ref>{{Cite journal|last=Fryer|first=Roland G|date=Spring 2007|title=Guess Who's Been Coming to Dinner? Trends in Interracial Marriage over the 20th Century|journal=Journal of Economic Perspectives|language=en|volume=21|issue=2|pages=71–90|doi=10.1257/jep.21.2.71|issn=0895-3309|citeseerx=10.1.1.169.3004}}</ref>