Intelligens och tillväxt

Vad bestämmer den ekonomiska tillväxten i ett land? Många menar att humankapitalet spelar en viktig roll, men trots det har ett antal empiriska studier, där humankapital mäts med hjälp av utbildningens omfattning, svårt att finna stöd för den tesen.*

På senare år har det föreslagits att utbildningens omfattning är ett dåligt mått på humankapital och att intelligens är ett bättre mått. Och mycket riktigt tycks effekten av intelligens på tillväxt positiv. Jones och Schneider sammanfattar sin studie** på följande sätt:

Human capital plays an important role in the theory of economic growth, but it has been difficult to measure this abstract concept. We survey the psychological literature on cross-cultural IQ tests and conclude that intelligence tests provide one useful measure of human capital. Using a new database of national average IQ, we show that in growth regressions that include only robust control variables, IQ is statistically significant in 99.8% of these 1330 regressions, easily passing a Bayesian model-averaging robustness test. A 1 point increase in a nation’s average IQ is associated with a persistent 0.11% annual increase in GDP per capita.

Weede och Kämpf finner i sin studie*** samma kvalitativa resultat:

Standard indicators of human capital endowment — like literacy, school enrollment ratios or years of schooling — suffer from a number of defects. They are crude. Mostly, they refer to input rather than output measures of human capital formation. Occasionally, they produce implausible effects. They are not robustly significant determinants of growth. Here, they are replaced by average intelligence. This variable consistently outperforms the other human capital indicators in spite of suffering from severe defects of its own. The immediate impact of institutional improvements, i.e., more government tolerance of private enterprise or economic freedom, on growth it is in the same order of magnitude as intelligence effects are.


*Se t.ex. s 138 ff i Temple, John (1999). ”The New Growth Evidence.Journal of Economic Literature 37(1): 112–156.
**Jones, Garett och Schneider, W. Joel (2006). ”Intelligence, Human Capital, and Economic Growth: A Bayesian Averaging of Classical Estimates (BACE) Approach.Journal of Economic Growth 11(1): 71–93.
***Weede, Erich och Kämpf, Sebastian (2002). ”The Impact of Intelligence and Institutional Improvements on Economic Growth.Kyklos 55(3): 361–380.