There has been a considerable amount of growth at the high end. But it's not being distributed down nearly as much as it once was. How many companies offer defined-benefit pension plans anymore, for instance? Nearly zero in the software industry; Garmin is the only one I know of that comes to mind. It's also well-known that executive compensation has skyrocketed while other wages have failed to keep up with inflation.

I don't think this is a complete explanation, though, and your point is a good one.

I also believe that the transition from one-income to dual-income households has had a pretty deleterious effect on the buying power of the average household. Rather than providing financial security, the second income led to a bidding war on homes, cars, and schools. It's a shocking fact that today's dual-income family has less disposable income after necessary bills than yesterday's single-income family.