As President Obama gears up to deliver a major address on the supposed successes of the Affordable Care Act, a study by one of the nation’s top health economists is pouring cold water on the ACA’s main engine for expanding health-insurance coverage: its expansion of Medicaid to cover able-bodied, childless adults.

MIT’s Amy Finkelstein has won a slew of awards, including the prestigious John Bates Clark Medal, for her work in health economics. In “The Value of Medicaid: Interpreting Results from the Oregon Health Insurance Experiment,” Finkelstein, Nathaniel Hendren, and Erzo Luttmer, used various econometric methods to quantify the benefits that enrollees receive from Medicaid. They drew from the Oregon Health Insurance Experiment, on which Finkelstein was a lead investigator.

The trio found that Medicaid enrollees receive very little benefit from each dollar spent on Medicaid. The absolute minimum enrollees receive is 15 cents of benefit per dollar spent. The authors’ best guess is that enrollees receive somewhere around 20-40 cents of benefit per dollar spent. The maximum is 90 cents–that is, no matter how the authors sliced the data, Medicaid’s costs exceed the benefits to enrollees. If the government just gave enrollees the money, Medicaid is such a bad deal that enrollees would not buy Medicaid coverage with it.

Medicaid spends, non-enrollees receive about 60 cents of benefit. The authors don’t identify who Medicaid’s real beneficiaries are, but they likely include those who receive Medicaid subsidies (hospitals, insurance companies, pharmaceutical companies, doctors, device manufacturers) and people who would otherwise make charitable contributions to provide medical care to enrollees. In other words, Medicaid’s actual beneficiaries are different from its intended beneficiaries.

That’s something to keep in mind when President Obama says, “There are outcomes we can calculate” like “the number of newly insured families” and that “those numbers add up to success.”