Blanket response to folks who propose store rationing.

1. Is this incentive compatible? No. Then we ought to expect cheating on any rationing.

2. If the store can ration, how can the store know how many people live in a particular family? A person shopping for a family of 12 will need more of everything than a family of 2. Should we expect stores to be able to determine this information? At what cost to the store?

The most likely outcome of rationing is that people will visit more stores, or visit the same store multiple times. In that case supplies will flow more readily to people who have a low opportunity cost of time. Then people who have a more difficult time getting out of the house, or who are more vulnerable when they do leave the house will have to spend more time in stores.

This is exactly the opposite of what we desire.

Prices overcome both the incentive problem from the first point, and the knowledge problem from the second point. They also discriminate on a different margin than time and public exposure.

Today, public exposure has very high social costs and ought to be discouraged and mitigated.

Conclusion: Prices have drawbacks. However, prices overcome incentive problems, knowledge problems, and reduce social costs. Use prices.