The renowned economist Erik Brynjolfsson recently asked: “At least so far, I haven’t seen any one suggesting to use the market system to allocate vaccines. Not even those who strongly advocate it in other areas. Why is that?”

As one of several people copied at the bottom of the tweet, I feel compelled to take up the challenge.

If you had to choose among those vaccines, wouldn’t it make sense to look for guidance from market prices? They will reflect information about the perceived value of both protection and risk. On the same principle, if you need brain surgery, you would certainly want to know what the brain surgeon charges, although of course that should not be the only factor in your decision.

The market prices for vaccines could be useful for other purposes as well. If scientific resources need to be allocated to improve vaccines or particular vaccine approaches, for instance, market prices might be useful signals.

Note also that the scope of the market might expand over time. In the early days of vaccine distribution, health-care workers will be a priority. Eventually, however, most of them will have access to vaccines. Selling off remaining vaccine doses might do more to encourage additional production than would bureaucratic allocation at a lower price.