John Kenneth Galbraith, one of the most famous practitioners of the high-minded guessing game known as economics, once noted that in the dismal science, “the majority is always wrong.” How else to explain the fact that so many economists upgraded their growth forecasts for the American economy at the end of last year, often to well above 3%, when the numbers so far this year have come in below 2%? The plunge is due to many things, from higher food and oil prices to supply-chain disruptions in the wake of the Japanese nuclear disaster to a terrible housing market.