Union Formation and Depression: Selection and Relationship Effects

Many studies have established that married people fare better than their never-married counterparts in terms of psychological well-being. It is still unclear, however, whether this advantage is due primarily to beneficial effects of marriage or to the selection of psychologically healthier individuals into marriage. This study employs data on young adults from both waves of the National Survey of Families and Households to test hypotheses based on both selection (N = 878) and relationship (N = 722) effects. Further, we differentiate union formation into cohabitation and marriage with and without prior cohabitation. Results indicate no evidence of selection of less depressed persons into either marriage or cohabitation, but a negative effect of entry into marriage on depression, particularly when marriage was not preceded by cohabitation. Key Words: cohabitation, depression, marriage, selection effect, union formation. Many studies have demonstrated that married persons fare better than the never-married on psychological well-being (Glenn & Weaver, 1988; Gove, Style, & Hughes, 1990; Kim & McKenry, 2002; Lee, Seccombe, & Shehan, 1991; Marks & Lambert, 1998; Simon, 2002; Stack & Eshleman, 1998); physical health (Waite, 1995; Waite & Gallagher, 2000); and life expectancy (Lillard & Waite, 1995; Murray, 2000). Two types of explanations have been proposed for the advantages of the married over the never-married. The first is the straightforward argument that married persons benefit directly from their relationships with their spouses, in terms of support, intimacy, mutual caring, companionship, and the financial advantages that come from pooling resources (Gove et al., 1990; Marks & Lambert, 1998; Ruvolo, 1998; Simon & Marcussen, 1999). Marriage also has a buffering effect against adverse life events or situations such as illness, poverty, or the loss of loved ones (Pearlin & Johnson, 1977). This argument implies that marriage improves psychological well-being, either directly or by moderating the effects of events and circumstances that would result in lower well-being for unmarried persons. This is often termed the social causation explanation (e.g., Simon, 2002), but we prefer the more specific term relationship effect. The second type of explanation is the selection effect, which postulates that happier, healthier people are more likely to be selected into marriage (Glenn & Weaver, 1988; Horwitz, White, & Howell-White, 1996; Mastekaasa, 1992). The selection effect implies an advantage of the married over the never-married in cross-sectional data, because those with the highest levels of well-being would be most likely to migrate from the never-married to the married category. The selection effect does not imply change in well-being for individuals accompanying the transition to marriage. The selection effect and relationship effect explanations are not at all mutually exclusive, however; both processes could operate simultaneously. Although it is possible to employ cross-sectional or cohort data to address the issue of relationship versus selection effects indirectly (e.g., Glenn & Weaver, 1988), panel data are obviously more useful. Several longitudinal studies have addressed this issue. The general consensus is that relationship effects are more powerful and more important than selection effects, although there is some evidence on each side. Mastekaasa (1992) found that a measure of life satisfaction predicted subsequent marriage for a sample of young adults in Norway, thus supporting the selection effect. Horwitz et al. (1996) reported that depression predicted subsequent marriage (negatively) for women, but not men, in a sample of never-married New Jersey residents. Several studies using the National Survey of Families and Households (NSFH; Kim & McKenry, 2002; Simon, 2002; Simon and Marcussen, 1999), however, observed no differences in depression at Time 1 between those who later married and those who remained single. …