Toys from shuttered Head Start program locations in Western Kentucky are stored in a warehouse in 2013. (Luke Sharrett/For The Washington Post)

Grover “Russ” Whitehurst, a senior fellow in economic studies at the Brookings Institution, directed the Education Department’s Institute of Education Sciences from 2002 to 2008.

For a half-century, our nation has focused on school-readiness programs such as Head Start as the best way to help low-income children escape the cycle of poverty. The idea is to level the playing field in cognitive and social skills by the time these children enter kindergarten so that they can keep pace with their more advantaged peers as they progress through school. In the next decade, we will spend $100 billion at the federal level just on Head Start, and all but a few states are funding their own pre-K programs.

Unfortunately, children who attend Head Start do no better in school than equivalent children who do not. Even the best pre-K programs’ positive impacts fade away in a couple of years, and some early-childhood programs actually leave children worse off than if they hadn’t participated at all.

Yet, early-childhood programs continue to get large amounts of taxpayer dollars, evidence be damned — something that is true of so many programs in Washington. Well-intentioned conventional wisdom wins out. Because low-income and minority kids enter school far behind their higher-income counterparts and don’t catch up, the theory of intervening early seems like common sense.

Which is why lately there has been a push by politicians to go one step further and create preschool programs for all, regardless of income. New York Mayor Bill de Blasio recently established such a program; Boston and the District are implementing them. Democratic presidential candidates Hillary Clinton and Bernie Sanders campaigned on plans to make universal pre-K a national priority. President Obama has proposed a federal-state partnership, called Preschool for All, that would leave taxpayers with a bill on the same order of magnitude as that for Head Start. The argument for this approach draws on the secret to the success of Social Security: The social compact (and the willingness to pay for it) works better if a program provides an entitlement for everyone.

But if our goal is to help poor families, is universal pre-K really the best, most efficient way? The answer is no.

I have compared the effects of direct income transfers to low-income families (such as the earned-income tax credit, or EITC) with programs designed to increase school readiness (universal preschool and Head Start). It turns out that putting money directly into the pockets of low-income parents, as many other countries do, produces substantially larger gains in children’s school achievement per dollar of expenditure than does a year of preschool or participation in Head Start. The results throw water on the conventional wisdom.

The results show that while the EITC isn’t specifically designed to boost academic achievement, it does so anyway — and not just for younger kids. The EITC is also a bargain compared with the programs specifically designed to help poor kids academically.

Specifically, each of four evaluations of U.S. family income support programs found substantially larger test score increases per $1,000 of public expenditure than resulted from programs specifically aimed at improving educational outcomes by focusing on school readiness. In particular, neither pre-K nor Head Start provided the same amount of improvement as the family support programs did. Other studies of the EITC also show impacts on even later outcomes — such as college enrollment and earned income.

The current annual federal expenditure on the EITC is about $65 billion. During the 2013 tax year, the average EITC was $3,074 for a family with children. In contrast, Head Start runs about $8,000 per child. Boston’s and the District’s pre-K programs run more than $16,000 per student. Spending less (EITC) is actually more effective than spending more (Head Start, universal pre-K). It’s a win-win.

Former senator Daniel Patrick Moynihan likened government bureaucracies dispensing social services to the poor as “feeding the sparrows by feeding the horses.” The school readiness option feeds the horses. Perhaps it is time to rethink our paradigm for supporting poor families. Let’s give them what they desperately need — more money — and let them decide how to spend it on the early care and education of their children.