I'm sure I've mentioned in earlier posts the notorious Bernie Madoff, who ran Bernard L. Madoff Investment Securities LLC from the day he started it up in 1960 until the day he surrendered to authorities in December 2008. Madoff’s crime, in common parlance, is that he was running a “Ponzi scheme.” This is a fraud in which early depositors are told their money has been invested in some wonderfully productive/reliable way, and they are receiving a share of the profits, when in fact what they are receiving are phony paper returns, from the deposits of other suckers. In Madoff’s case, the Ponzi scheme seems to have been adopted in a very cold-blooded way and operated for decades before it finally became unsustainable. I mention him here because I've been giving some thought to the fact that sometimes the development of a Ponzi scheme is not quite so cold-blooded. Sometimes an asset manager will bumble into running a Ponzi scheme by degrees. [I a...