My long answer: the economic growth of the 1990s went mainly to the upper classes (median wages hardly grew at all, especially when you take rising health-insurance costs into account). Instead of consuming their profits, the people in the top brackets keep looking for things to invest in. People who want to invest conservatively are pouring money into T-bills (thus, in spite of the massive deficit, Treasury rates are still quite low). People who want to be aggressive once invested in dot-coms, then stampeded to real estate and too-clever-by-half financial instruments, and now are pouring money into social media. Capital will continue to flit from one bubble-opportunity to another until the people at the bottom of the pyramid have more actual money to spend.
My long answer: the economic growth of the 1990s went mainly to the upper classes (median wages hardly grew at all, especially when you take rising health-insurance costs into account). Instead of consuming their profits, the people in the top brackets keep looking for things to invest in. People who want to invest conservatively are pouring money into T-bills (thus, in spite of the massive deficit, Treasury rates are still quite low). People who want to be aggressive once invested in dot-coms, then stampeded to real estate and too-clever-by-half financial instruments, and now are pouring money into social media. Capital will continue to flit from one bubble-opportunity to another until the people at the bottom of the pyramid have more actual money to spend.