The study "warns that low civilian casualty estimates may provide false assurance to the public and policymakers that drone strikes do not harm civilians." Many low-ball estimates - like those from Long War Journal and New America Foundation - are due to reliance on news reports, which "suffer from common flaws" like trusting "anonymous Pakistani government officials or unnamed witnesses for the claim that 'militants' - rather than civilians - were killed."
"In the rare but significant cases where on-the-ground reporting has offered evidence of civilian deaths from drone strikes," the report's press release said, "the U.S. government has failed to officially respond or provide information about whether it conducts its own investigations into potential civilian deaths. The report calls on the government to investigate reports of civilian casualties, track and release drone strike casualty information, and disclose the standards and definitions it uses to categorize individuals as subject to direct attack."
The report focuses on how news reports as well as these tracking organizations can get sloppy when identifying civilian casualties. But it leaves out how the Obama administration has chosen to count civilians. According to the New York Times, the administration "counts all military-age males in a strike zone as combatants...unless there is explicit intelligence posthumously proving them innocent."
Comment: But since the U.S. is neither sharing any useful data about these murderous activities, nor gathering facts from reliable sources on the ground, it seems highly improbable that anyone is going to be 'posthumously proven innocent'. Or that the media would report it even if it were so. Business as usual, murder with impunity.
Academia seems to have begun to pay more attention to the drone war. Follow up reading this study by reading last month's study from the Stanford and NYU schools of law - Living Under Drones.