With the United States and European economies having slowed markedly according to the latest data, and with global growth continuing to disappoint, a reasonable question increasingly arises: Are we in another Great Depression? The easy answer is "no" - the main features of the Great Depression have not yet manifested themselves and still seem unlikely. But it is increasingly likely that we will find ourselves in the midst of something nearly as traumatic, a long slump of the kind seen with some regularity in the 19th century, particularly if presidential election-year politics continue to head in a dangerous direction. The...