Meanwhile, fewer and fewer families in need are receiving direct cash support—an essential resource for reducing levels of child poverty.

To understand why a state’s racial composition is the strongest predictor of how it allocates TANF resources, consider that academic research has shown time and time again that many Americans tend to view black families as lazy, unworthy of help, and receiving “more than they deserve” from the state. Whether researchers are exploring Why Americans Hate Welfare, as Martin Gilens did in his 1999 book, or asking “Why Doesn’t the U.S. Have a European Welfare State?,” as Alberto Alesina and colleagues asked in 2001, the answer nearly always begins and ends with evidence of racialized perceptions of the beneficiaries of social assistance. These perceptions have crept into many policy-making decisions, including those relating to TANF. Indeed, my results show that—unlike race—the share of single mothers in the state, a state’s wealth, or which political party has control of its legislature explains little of the variance in states’ cash-assistance spending.

Removing the racial inequities in states’ TANF allocations would mark a large step in reducing racial differences in child poverty. For context, the estimated 15 percent reduction in the black-white child-poverty gap is comparable to the effect of moving all children from single-mother households into two-parent households (while keeping all other characteristics of the households as is).

This is not to say that single motherhood is unimportant—more children growing up in two-parent households would surely be a good thing. But if a state’s purported goal is to reduce the number of its residents living in poverty, offering cash support coupled with employment incentives is likely to be more effective than sex-education courses or ad campaigns “promoting the value of healthy marriage.”

TANF is not the only social program in the U.S. that stratifies low-income families based on state boundaries and skin color. In Jamila Michener’s new book, “Fragmented Democracy: Medicaid, Federalism, and Unequal Politics,” the Cornell political scientist depicts in vivid detail how state differences in Medicaid policies “tether health policy even more deeply to race and poverty.”

Most concretely, Michener points out that eight of the 11 states with the largest share of the nation’s black population are among those that have failed to implement Medicaid expansion. Even among Medicaid beneficiaries, access to dental treatment, hearing or vision support, and end-of-life services vary by state. If a person eligible for Medicaid “got sick in the wrong state during the wrong year,” Michener writes, “the consequences of policy fragmentation could be life altering.”

Other examples of “policy fragmentation” abound. Today, roughly half of the 50 states offer a supplement to the federal earned-income tax credit, but the average black family is less likely than the average white family to live in one of those states. States vary in levels of minimum wage, paid-leave policies, and investments in early-childhood education, but again, regional and racial inequities are large. And perhaps most damaging, states have long varied with respect to their criminal-justice policies. In 11 states, at least one in 20 black men is incarcerated. Ironically, the states most likely to chide black women for raising children alone—and to promote marriage as the key to poverty reduction—tend to be the same states that incarcerate the largest share of black men. Including the incarcerated population in our estimates of poverty in the U.S. would only widen racial divides.