Last year the Education Department announced that math and reading scores on the National Assessment of Educational Progress had declined since 2013. Though the decline was small (and not much to worry about), the announcement ruined the Obama administration’s case that its education policies were vindicated by rising scores. Now a new report from the Institute of Education Sciences (IES) has questioned the efficacy of one of the most consequential of those policies – the “Race to the Top” grants.

Race to the Top helped spur the widespread adoption of the (in)famous Common Core standards. It was a $4 billion competitive grant program that incentivized states to adopt preferred federal policies on everything from teacher evaluation to charter schools to learning standards. States with the best reform proposals received cash grants in return.

Did Race to the Top improve student achievement? It is impossible to know for sure without a randomized experiment, but the IES report offers a reason to be skeptical: Race to the Top generally does not appear to have altered test-score trends in participating states. It reminds me of Charles Murray’s “trend-line test” as a prima facie evaluation of government programs. If the introduction of a government program changes the trend line of whatever outcome it was intended to influence, then there is a (superficial) case for its effectiveness. Oftentimes, however, even major policy changes seem to have little effect on trends. That is the case now with Race to the Top.

The trend-line test is not conclusive, of course, since what would have happened in the absence of Race to the Top is unknown. As IES notes, one could imagine all sorts of alternative histories – e.g., “test scores were about to plunge if not for Race to the Top” — that could cast the program’s impact as either positive or negative. Nevertheless, the stubborn trend lines should be sobering for advocates who believe that big test-score changes are just a matter of pulling a few levers and pushing the right buttons.

Maybe none of this matters anymore, as Education Week has suggested, since Race to the Top is over and Congress has barred the Department from restarting it. But part of Race to the Top’s legacy is the hasty adoption of Common Core, a major centralizing force in American education. As I’ve stated before, the government’s nature is to persistently centralize and expand, regardless of whether it has strong theoretical and empirical reasons for doing so.