 The existence of a social gradient in health certainly suggests that something in addition to health care exercises a powerful influence on an individual’s health—something, moreover, that at least correlates with a social variable. However, it is not clear exactly what this something is. To begin with, similar domestic gradients in individual life expectancy can be found when the social variable is income (Chetty et al. 2016; Case, Lubotsky, &amp; Paxson 2002; McDonough et al. 1997); when it is education (Mackenbach et al. 2008; Huisman et al. 2005; Crimmins &amp; Saito 2001; Elo &amp; Preston 1996; Kunst &amp; Mackenbach 1994); when it is social class (Wilkinson &amp; Marmot 2003); and, in the U.S. context, when it is race (Arias 2016; Braveman, Cubbin, et al. 2010).