I had an economics prof. that spent an entire lecture on various forms of, shall we say, odd indexes, linking to the economy.
You are familiar with the skirt index, the higher the hemline, the better the economy. Did you know about the Sports Illustrated Swimsuit Model index? Why yes, American Blonde's predict better times ahead. (This year's model was a blonde Israeli)
Finally, we come to the underwear index. In times of economic prosperity, the sales of men's underwear are steady, but flat. The sale of men's underwear drops off sharply in times of recession.
It seems to me the cure for economic doldrums is at hand, within our reach. Everyone, go buy your husband some underwear! Don't have a husband, buy some for your brother, your boss. After all, it's patriotic to help the economy.