As detailed by Ph.D. economist Sean Flynn (and other scholarly sources), the "only way to cover" the costs of forcing health insurance companies to issue coverage to uninsured people with preexisting conditions "is to charge high premiums, getting enough money out of those without preexisting conditions to pay the expected costs." Likewise, an academic textbook on healthcare accounting explains that "if individuals are covered for preexisting conditions but don't have to buy insurance until they get sick, premiums for everyone could rise so high as to make it nearly impossible for anyone to afford health insurance." A 2016 report by Blue Cross Blue Shield found that in the wake of the Obamacare mandate on preexisting conditions, newly insured people "used more medical services across all sites of care" than people who previously had coverage.