In this season given to tidings of comfort and joy, word has come that we New Yorkers are the sad sacks of the United States. This is something of a surprise. Sure, we complain a lot. Grumbling could qualify as the official state sport. But are we really the unhappiest of them all? It seems so, judging from a study by two economics professors, newly published in Science magazine. The academics — Andrew J. Oswald, of the University of Warwick in Britain, and Stephen Wu, of Hamilton College in Clinton, N.Y. — examined piles of data, tossed them into a...