Does Joint Physical Custody “Cause” Children’s Better Outcomes?

ABSTRACT

Policymakers and researchers are concerned with whether joint physical custody (JPC) produces better outcomes for children than sole custody. Although several review articles summarizing up to 61 empirical articles demonstrate very positive answers, many of the research designs used compromise the ability to claim that it is JPC per se—and not selection effects—that causes the effect. We discuss several research design issues, such as propensity score analysis, that can more powerfully probe the question of causality. Some studies have already been conducted employing these strategies and more are recommended and likely to soon be forthcoming. On the basis of this comprehensive review we conclude that JPC probably does cause benefits to children on average, and that social scientists can now provisionally recommend rebuttably presumptive JPC to policymakers.

KEYWORDS:

• Joint custody
• shared parenting
• causal inference
• divorce

Notes

1. There is also, of course, a very substantial literature that opposes shared parenting presumptions when domestic violence is evident or alleged (e.g., Greenberg, 2004; Morrill, Dai, Dunn, Sung, & Smith, 2005). Although these voices are persuasive, in general, the articles provide arguments, not quantitative empirical research findings. Because this article is devoted to research design issues within the quantitative empirical research literature, papers presenting arguments only are outside the scope of this article. In any event, proposed statutes often explicitly note that the existence of chronic, one-sided domestic violence should be a rebuttal factor. There are also voices that oppose shared parenting when there is high interparental conflict. For example, Stahl (1999), in his guide for professional custody evaluators, opined, “high conflict parents cannot share parenting” (p. 99). Similarly, Buchanan (2001) wrote, “when parents remain in high conflict, joint custody is … ill-advised” (p. 234). Emery (2009) wrote, “joint physical custody is the worst arrangement for children when [it] leaves [them] in the middle of a war zone. … In high conflict divorces, children do worse in joint physical custody than in other arrangements.” Such claims are supposedly based on the quantitative empirical literature and therefore are included in our review here.