"It turns out there are strong economic incentives for doctors to keep patient information to themselves — and even stronger incentives for electronic medical records not to play nicely with each other."

"While patients might want one hospital to exchange information with another hospital, those institutions have little incentive to do so. A shared medical record, after all, makes it easier to see a different doctor. A walled garden — where records only get traded within one hospital system — can encourage patients to stick with those providers."