Kids With Degrees But Low GDPs

Although investing in education leads directly to higher incomes at the individual level, Charles Kenny notices that the connection doesn’t seem to hold at the national level. He wonders why:

Analysis by Lawrence Katz and Claudia Goldin suggests that increased educational attainment among Americans from 1915 to 1999 might account for 10 percent of the growth in U.S. GDP over that time. Some commentators contend that this an underestimate (PDF). But at the global level, no relationship has been found between a more educated population and more rapid economic development. There has been an explosion in schooling in developing countries, but many show nothing like explosive growth in GDP per person. By 2010, the average Kenyan had spent more years in school than the average French citizen had in 1985. But Kenya’s GDP per capita in 2010 was only 7 percent of France’s GDP per head 25 years earlier.

What explains the limited impact of increased education on economic growth?

A possible answer is that education acts as a filter rather than an investment. A recent study (PDF) in Italy found that test scores had a significant impact on the earnings of employees—but none on the earnings of self-employed people. One interpretation of that result is that schooling signals persons with intelligence and ambition, rather than actually imparting or indicating skills that make them better at their jobs over the long term. Signaling helps as a screening tool for employers, but makes no difference to people who work for themselves. Presumably, they already know how smart and ambitious they are.