“Secretary of Education Margaret Spellings will require all states to use one federal formula to calculate graduation and dropout rates,” reports the New York Times, as part of a campaign to keep more kids in school.

The idea that we can reduce the public school dropout rate simply by measuring it better is misguided. It’s like believing that the North Koreans could improve their economy by more accurately measuring the number of people who are starving. As with the North Korean economy, the problem with U.S. public schooling is that it is a monopoly that takes choice away from families, takes professional autonomy away from educators, and takes normal economic incentives away from everyone.

Meanwhile, there is evidence from a sophisticated nationwide study that inner city minority kids — those most at risk of dropping out — are more likely to graduate, more likely to get into college, and more likely to graduate from college if they attend private instead of public schools — and that’s true after controlling for differences in student and family background. Other small scale studies of the Milwaukee school voucher program show similar results.

We already know how to reduce the dropout rate: ensure that all families can easily afford to choose the public or private schools best suited to their children. Until that happens, expect to see millions of American kids continuing to starve for a real education.