A new study is questioning long-held government claims that background checks on private gun transfers could help stop mass public shootings.

The report, published by the Crime Prevention Research Center on Jan. 2, argues that not only are background checks expensive, but that they have failed to thwart mass public shootings.

The findings come as President Obama on Tuesday formally announced plans to expand background checks and make other changes to America’s gun rules through executive action. The White House has aggressively pushed for background checks following mass public shootings.

After the December murders by a husband and wife terror team in San Bernardino, Calif., Obama told the nation there were steps the U.S. could take to “improve the odds that they don’t happen as frequently: commonsense gun safety laws, stronger background checks.”

The study, however, states that the initial data on universal background checks does not confirm the claims of supporters and the White House.

“Despite the frequent calls for expanded background checks after mass public shootings, there is no evidence that background checks on private transfers of guns would have prevented any of the attacks that have taken place since at least 2000,” the study states, adding that there is no statistical evidence that proves the mass public shootings are “rarer in states with background checks on private transfers.”

“Simple regression estimates provide no support for the claim that background checks reduce mass public shootings or the harm from those attacks,” the study states. “Mass public shootings may vary between states for many reasons that have nothing to do with background checks.”

Since 2013, states with “universal” background checks have had 124 percent more mass public shootings and dramatically higher rates of death and injury.

“Per capita, there were 267 percent more deaths and 1,431 percent more injuries,” the study states.

The study also found the per capita rate of deaths and injuries from mass public shootings increases after states pass stricter background checks on private transfers.

In addition, the study calls out the costs of expanding background checks to private transfers – specifically, the fees attached to private transfers.

“Law-abiding poor blacks who live in high crime urban areas and who benefit the most from protecting themselves will be the ones most likely priced out of owning guns for protection,” the study finds. “Without some benefits in terms of either reduced crime or mass public shootings, it is hard to see how these rules pass any type of cost-benefit test.”

Obama, speaking Tuesday at the White House, acknowledged that the changes can’t stop “every act of violence.” But he said, “We maybe can’t save everybody but we could save some.”

Federal law requires a criminal and mental illness background check for every person who buys a gun through a federally licensed dealer. Felons as well as those who have been involuntarily committed for mental illness are banned from buying a gun.