The uncertainty in question will not be an accident of our circumstances — it will be entirely deliberate. We want to tempt others to engage in economic behavior, the output of which is uncertain, at the opportunity cost of behavior that is presumably much more certain. In effect, we are buying uncertainty with certainty.

For these reasons, prices may pass statistical tests for randomness, but they are not themselves random (although it is plausible that their randomness is random, and that randomness is random, and so on) but rather are unpredictable on the basis of market data alone. They are, however, predictable to the extent that the predictor accurately assess

Say you are a pension fund that needs an 8% return to meet its liabilities without difficulty. And say that stocks have been inflated to the point that you can in all honesty expect only a 2% return over the long run from here given reasonable assumptions about valuation metrics returning to something sensible at some point. You might be tempted to