of life. We also find highly acceptable what contributes most to self-esteem." Economic and social behavior, Galbraith con- tinued, "are complex, and to comprehend their character is mentally tiring. Therefore we adhere, as though to a raft, to those ideas which represent our understanding." So the conventional wisdom in Galbraiths view must be simple, convenient, comfortable, and comforting-though not necessarily true. It would be silly to argue that the conventional wisdom is never true. But noticing where the conventional wisdom may be false- noticing, perhaps, the contrails of sloppy or self-interested thinking- is a nice place to start asking questions. Consider the recent history of homelessness in the United States. In the early 1980s, an advocate for the homeless named Mitch Snyder took to saying that there were about 3 million homeless Americans. The public duly sat up and took notice. More than 1 of every 100 people were homeless? That sure seemed high, but . . . well, the ex- pert said it. A heretofore quiescent problem was suddenly catapulted into the national consciousness. Snyder even testified before Congress about the magnitude of the problem. He also reportedly told a college audience that 45 homeless people die each second-which would mean a whopping 1.4 billion dead homeless every year. (The U.S. population at the time was about 225 million.) Assuming that Snyder misspoke or was misquoted and meant to say that one homeless per- son died every forty-five seconds, thats still 701,000 dead homeless people every year-roughly one-third of all deaths in the United States. Hmm. Ultimately, when Snyder was pressed on his figure of 3 million homeless, he admitted that it was a fabrication. Journalists had been hounding him for a specific number, he said, and he hadnt wanted them to walk away empty-handed.     It may be sad but not surprising to learn that experts like Snyder