He wants to punish such people. The economics of this is really terribly, terribly, simple. As a result of the disaster--of any disaster that is--some things are in short supply. Perhaps because some of the supply got damaged, or perhaps because people need to substitute. Floods could, for example, knock out the municipal water supply, leaving people needing bottled water. So relative to the available supply demand has risen. We now need some method of rationing that limited and scarce supply over that increased demand. Rationing by price is always the efficient way of doing this.

We also want something else to happen--we want supply to increase as fast as we can manage that. As we know from our basic Econ 101 supply and demand curves the way to increase supply is for the price to increase. We want, for example, people to start trucking bottled water from Louisiana to Texas. More money to be made by doing so will encourage people to do so. And as that extra supply arrives then prices will go down again as demand is met.