This article considers whether the disparate socioeconomic circumstances of families in which white, black, and Hispanic children grow up account for the racial and ethnic gaps in school readiness among American preschoolers. It first reviews why family socioeconomic resources might matter for children's school readiness. The authors concentrate on four key components of parent socioeconomic status that are particularly relevant for children's well-being--income, education, family structure, and neighborhood conditions. They survey a range of relevant policies and programs that might help to close socioeconomic gaps, for example, by increasing family incomes or maternal educational attainment, strengthening families, and improving poor neighborhoods. Their survey of links between socioeconomic resources and test score gaps indicates that resource differences account for about half of the standard deviation--about 8 points on a test with a standard deviation of 15--of the differences. Yet, the policy implications of this are far from clear. They note that although policies are designed to improve aspects of "socioeconomic status" (for example, income, education, family structure), no policy improves "socioeconomic status" directly. Second, they caution that good policy is based on an understanding of causal relationships between family background and children outcomes, as well as cost-effectiveness. They conclude that boosting the family incomes of preschool children may be a promising intervention to reduce racial and ethnic school readiness gaps. However, given the lack of successful large-scale interventions, the authors suggest giving only a modest role to programs that address parents' socioeconomic resources. They suggest that policies that directly target children may be the most efficient way to narrow school readiness gaps. (Contains 4 figures, 1 table and 68 endnotes.)