I very much agree with the gist of Nassim Nicholas Taleb’s new book, The Black Swan: The Impact of the Highly Improbable (London: Allen Lane, 2007), which you review (“The Perils of Prediction,” June 2, 2007). Indeed, successful companies and financial institutions owe as much to luck as to skill. Just watch them over a bit longer time span. Where I take issue with him is elsewhere. The distinction between uncertainty and risk in economics was made clear by Frank Knight nearly a century ago, but there has been a secular drift away from uncertainty and toward risk ever since. “Assume,” risk analysts are wont of saying, “that outcomes of a certain action can be enumerated, as well as that the probabilities of these outcomes and their impacts can be assessed with a sufficient degree of certainty.” Given such assumptions, risk analysis proceeds smoothly if fallaciously, as its ultimate results have much in common with astrology, which can also get quite involved technically speaking. Whence such abominable assumptions, which are sanctioned even by our institutions of higher learning? From the insatiable human need to foresee the future. The future will be made known at any cost. Charlatans of all sorts, including risk analysts, will always be in plentiful supply given such irrational demand. To wit, the admonishment must be squarely addressed to the demanders rather than the suppliers.