When my wife was a liberal, she complained that libertarian reasoning is coldhearted. Since markets produce winners and losers — and many losers did nothing wrong — market competition is cruel. It must seem so. President Obama used the word “fair” in his last State of the Union address nine times.

We are imprinted to prefer a world that is “fair.” Our close relatives the chimpanzees freak out when one chimp gets more than his fair share, so zookeepers are careful about food portions. Chimps are hardwired to get angry when they think they’ve been cheated — and so are we.