Moral Decline or Moral Progress?

People worry a lot about declining moral values in our modern world. Commenter Evan at econlog offers a different perspective on that, in a vigorous debate about Bryan Caplan's claim that average people today have more material comforts than George Vanderbilt, the builder of Biltmore, had:

One thing I haven't heard anyone address yet is moral progress. The values of earlier time periods were sickeningly depraved. One reason I'd never want to have been born in the past, rather than today, even if my past status would have been higher, is that I enjoy being the kind of person who doesn't burn witches, own slaves, participate in pogroms, or bash gays. I think if you asked most poor people if they'd rather be a wealthy slaveowner in the past, they'd all look at you with horror.