Sometimes prices go up. This has happened before and will happen again. This hurts poor people more than it hurts the rich: poor people already spend most of their money. When prices go up, they can't get everything they need. Things get worse. There is unrest. There is war. There may be famine. There may be plague. Eventually, the thing that was causing the worst price pressure eases off. Things head back to normal. But a lot has gone wrong in the meanwhile.
This book has awesome charts. I almost wanted the guy to shut up about the reasons behind past price-hikes because they were distracting me from all of the excellent data. Prices versus time. Population versus plagues. Prices versus population. In an appendix, there is a chart plotting The Price of Donkeys in Roman Egypt, as measured in Egyptian drachme per head. If I were a publisher I would insist that all books from now on contain an appendix with a chart plotting the Price of Donkeys in Roman Egypt.
This book taught me a lot. The next time some free-market fiend tells me "Price controls don't work," now I can cite a time when they did work quite effectively. Must remember. Harry Truman. 1951. Korean War. Also, WWII.