Previously, that wasn't entirely true. In the very early nineties, insurance companies lured doctors in with promises of referral if they would just accept cer

Previously, that wasn't entirely true. In the very early nineties, insurance companies lured doctors in with promises of referral if they would just accept certain terms. Originally, this was to the benefit of the doctor -- more referrals. But only originally: once lock-in occurred, the insurance companies began to set their own terms. They couldn't have accomplished this without some greed on the part of many doctors early on.