Ideally the answer is NO the doctor can ask for payment but the payee in this case need not pay for services where there is no explicit contract. In this case the doctor is risking not being paid. So what, we all do this. Did you ever help a person and realize that you spent so much time that you should have charged them?
It is only government that steps in here and tries to provide compensation for the doctor to keep them from working for free with all sorts of unintended consequences.
And in a more free world, doctors and hospitals would be advertising they helped these types of persons who could not pay them. Would you go to a hospital that helps you out in a pinch or would you go to the one that stiffs the poor sap dying on the side of the road?
Therefore, I agree with Posner that judges should make decisions that would closely match the market outcomes that would have emerged had transaction costs not been so high. In this case, I think it is fair to say that 9/10 of people dying on the street would have agreed to pay the doctor to help them. So the judge’s decision should reflect that.
Before I get much into this, because I’m not sure if I agree with this:
Could you consider words like “Emergency” automatically implying non economic terms / externality? If that’s the case what would market costs have to do with anything?