text:  And that is Al Roth himself. He teaches at Stanford. He points out that repugnance doesn't always affect markets the way you might think. I find it very hard to predict. And one reason it's hard to predict is it's different in different places. Disgust is easy to predict. If someone spits into your coffee, you won't finish your coffee, no matter where in the world you are. But kidney exchange, surrogacy, prostitution, those are things that are repugnant in some places and not in others. Horse meat.