December 25, 2008

GDP vs. Household Income

Yangshen Huan writes in the The Wall Street Journal about misguided focus on GDP and other simplistic measures of economic prosperity.

The fundamental problem, and a mortal bias of economists, is a fixation with simple measurements -- especially GDP data. Ask a professional economist how many provinces China has and you are likely to draw a blank stare. But ask him what the GDP growth of China has been and he'll quickly be able to tell you that China has grown at a double-digit rate for 30 years and that at this rate China will overtake the U.S. by 2035 (or some other date). GDP-centrism is endemic, and often comes at the expense of deeper analysis. Just look at the enthusiasm with which economists and analysts greeted Goldman Sachs's famed "BRIC" report forecasting dramatic booms in Brazil, Russia, India and China -- a report based on little more than fifth-grade mathematics.

This obsession with China's impressive GDP growth often ignores discussion of what's causing that growth and whether it's self-sustained. This is where the decoupling enthusiasts stumbled, and where policy makers can still go seriously wrong. Consider, for example, data about the very slow growth of household incomes in China. This is particularly apparent in rural households. For the past 20 years or so, rural household income has grown at a rate half that of GDP growth. The slow household income growth, combined with rapid GDP growth, means that China has created a huge production capacity but it has done so at the expense of its own consumption base. This fact alone should have disproved the decoupling hypothesis. All the new "excess" production had to go somewhere, i.e., to the U.S. What's more, the persistence of this gap suggests that over time, China's growth has become more, not less, a derivative of America's consumption appetite.

This is a global phenomenon, and not strictly restricted to China. Overflowing credit and growing income inequality have caused individual consumer incomes to stay way behind the overall size of the economy all over the world.

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