Great Stagnation -- I believe that the rich world's economy IS in a great stagnation that has lasted for most of a century, but NOT for the reasons Cowen and Thiel suggest. The stagnation is because of "progressive" politics, especially both the welfare state and overregulation/nanny-statism, which destroy most people's opportunities to innovate and profit by it.

I get the impression that this is actually a core part of Thiel's argument. Consider this, for example.