I've been meaning to comment on Tyler Cowen's ebook The Great Stagnation for a while. The book relies heavily on two claims: 1) There has been a dramatic slowdown in productivity in the past ~40 years, attributable to us exhausting all the low-lying fruit; and 2) Household income has similarly fared poorly in this period.
I can't really comment on 1), which I grant seems true enough. But I've written some on 2), relying on the work of Terry Fitzgerald, which I'll copy here from e21:
1. Inflation. The price indices used to compute per capita income are different from those designed to compute median household income. The price indices typically used for household income (Chart 1) are taken from a composite of sources, some of which take into account the prices faced by wage earners. The price index for national labor surveys (Chart 2) on the other hand, corrects prices on the basis of personal expenditures – the basket of goods consumed every year. These different series have different measures of inflation, and so result in different estimates of real income. A true apples-to-apples comparison results in a closer match between these two graphs, favoring the depiction in Chart 2.
2. Fringe benefits. Employers are increasingly likely to compensate workers in the form of fringe benefits, rather than cash income. In part, this is because certain fringe benefits, like employee-provided health insurance, are exempt from taxes. Estimates of household income do not take these into account, while they are an important part of the economy.
This is an important adjustment to consider, because we are frequently concerned with the overall quality of life for households, rather than the mechanism by which they consume goods.
Simply taking the first two points into account (using a common price index and counting fringe benefits) results in compensation that has grown 28% from 1976 to 2006 for the median worker, rather than stagnating.
3. Changing Composition of Households. Fewer people live in each household today than they did thirty years ago, and so gains in household income are divided against a greater number of households. While 64% of households consisted of married couples in 1976, this was true of only 51% of households in 2006.
Fitzgerald finds that every household type had large gains in income growth – gains obscured due to the changing composition of households. Married couples saw household income gains of 42% from 1976 to 2006, while single-female residences saw gains of 56%.
To be sure, inequality may account for some of the difference between household income and aggregate income. Fitzgerald estimates that Census income per person grew by 65%, while median income per person grew by around 50%. The remaining difference may be accounted for by a rise in inequality. But the important point is that households are not stagnating in the aggregate. America’s phenomenal productivity gains have reached its households.