> As I understand it, salaries are only one of the many ways that doctors make money. Many "providers" are doctor-owned.
No, nowadays, private practices are a dying breed. Most physicians are, in fact, salaried. And that salary isn't actually all earnings, because a large chunk of their business and professional expenses (insurance, continuing education, various licenses, etc.) all have to be paid out-of-pocket. These expenses are not generally tax-deductible, because of the AMT thresholds, so doctors' actual disposable income is dramatically less than you would think just by looking at the raw salary number. It's very different from other fields (like software engineering) in this regard.