Garett Jones

2D:4D Asymmetry and Gender Differences in Academic Performance

Exposure to prenatal androgens affects both future behavior and life choices. However, there is still relatively limited evidence on its effects on academic performance. Moreover, the predicted effect of exposure to prenatal testosterone (T)–which is inversely correlated with the relative length of the second to fourth finger lengths (2D:4D)–would seem to have ambiguous effects on academic achievement since traits like aggressiveness or risk-taking are not uniformly positive for success in school. We provide the first evidence of a non-linear, quadratic, relationship between 2D:4D and academic achievement using samples from Moscow and Manila. We also find that there is a gender differentiated link between various measures of academic achievement and measured digit ratios. These effects are different depending on the field of study, choice of achievement measure, and use of the right hand or left digit ratios. The results seem to be asymmetric between Moscow and Manila where the right (left) hand generates inverted-U (U-shaped) curves in Moscow while the pattern for hands reverses in Manila. Drawing from unusually large and detailed samples of university students in two countries not studied in the digit literature, our work is the first to have a large cross country comparison that includes two groups with very different ethnic compositions.

U.S. Troops and Foreign Economic Growth

Do American troops help or hinder economic growth in other countries? We consider a newly constructed dataset of the deployment of U.S. troops over the years 1950–2000 and discover a positive relationship between deployed troops and host country economic growth, which is robust to multiple control variables. Each tenfold increase in U.S. troops is associated with a one–third percentage point increase in average host country annual growth. We explore three possible causal explanations: a Keynesian aggregate demand boost; the diffusion of institutions; and security. Extensive econometric testing, including the use of panel data, confirms the core relationship.

IQ and Entrepreneurship: International Evidence

National measures of cognitive skill, including IQ tests, have received attention recently as a possible driver of cross-country productivity differences. In a parallel literature, national measures of entrepreneurial activity and pro-entrepreneurship policies have received similar attention. This paper is the first to demonstrate that higher national average IQ reliably predicts higher ratings for the Acs-Szerb Global Entrepreneurship Development Index (GEDI). Results hold after controlling for GDP, education levels, inequality, broad economic freedom indices, and other factors. Microfounded explanations for these results are considered.

Human Capital in the Creation of Social Capital: Evidence from Diplomatic Parking Tickets

We provide evidence that individuals selected from societies with high human capital are more likely to cooperate when placed in an environment comparable to the state of nature: The world of New York City diplomatic parking. National average IQ, a robust predictor of economic growth, is found to be a robust (negative) predictor of the number of unpaid parking tickets issued to a countrys diplomatic delegation at the United Nations. Average years of education have a similarly strong relationship with civil behavior. Results hold after controlling for GDP per capita and corruption in the diplomats home-country. We integrate this result into the experimental game theory literature on cognitive skills and pro-social behavior.

IQ in the Ramsey Model: A Naive Calibration

I show that in a conventional Ramsey model, between one-fourth and one-half of the global income distribution can be explained by a single factor: The effect of large, persistent differences in national average IQ on the private marginal product of labor. Thus, differences in national average IQ may be a driving force behind global income inequality. These persistent differences in cognitive ability--which are well-supported in the psychology literature--are likely to be somewhat malleable through better health care, better education, and especially better nutrition in the world’s poorest countries. A simple calibration exercise in the spirit of Bils and Klenow (2000) and Castro (2005) is conducted. I show that an IQ-augmented Ramsey model can explain more than half of the empirical relationship between national average IQ and GDP per worker. I provide evidence that little of the IQ-productivity relationship is likely to be due to reverse causality.

IQ and the Economic Growth of U.S. States

In the cross-country literature, cognitive skills are robust predictors of economic growth. We investigate claims by psychologists that the same is true at the state level. In a variety of specifications using four proxies for average state IQ used in the psychology literature, little evidence is found for a robust IQ-growth relationship at the state level.

2D:4D Asymmetry and Academic Perfomance: Evidence from Moscow and Manila

Exposure to prenatal androgens affects both future behavior and life choices. However, there is still relatively limited evidence on its effects on academic performance. Moreover, the predicted effect of exposure to prenatal testosterone (T) - which is inversely correlated with the relative length of the second to fourth finger lengths (2D:4D) - would seem to have ambiguous effects on academic achievement since traits like confidence, aggressiveness, or risk-taking are not uniformly positive for success in school. We provide the first evidence of a non-linear relationship between 2D:4D and academic achievement using samples from Moscow and Manila. We find that there is a quadratic relationship between high T exposure and markers of achievement such as grades or test scores and that the optimum digit ratio for women in our sample is lower (indicating higher prenatal T) than the average. The results for men are generally insignificant for Moscow but significant for Manila showing similar non-linear effects. Our work is thus unusual in that it draws from a large sample of nearly a thousand university students in Moscow and over a hundred from Manila for whom we also have extensive information on high school test scores, family background and other potential correlates of achievement. Our work is also the first to have a large cross country comparison that includes two groups with very different ethnic compositions.

U.S. Troops and Economic Growth

In the midst of a major U.S. military effort in Iraq and the Middle East, economists should be able to assess the relationship between U.S. troops and growth. The necessity of military force in providing security for nation-building is a common assumption among policymakers and international affairs experts, but there has never been an econometric analysis of the impact of troops on growth. We use a newly constructed disaggregated dataset on the deployment of U.S. troops over the years 1950-2000, and discover a positive relationship with host country economic growth, robust to multiple control variables.

The liquidity effect across the short end of the term structure

Because the Federal Reserve is constantly responding to developments in the economy, it has been difficult to come up with convincing estimates of the effects of exogenous shifts in money supply on interest rates. This study uses exogenous, well-identified reserve supply shocks to estimate how money supply shocks that last one day impact short-term interest rates. The results imply that the one-day liquidity effect is substantial, and that it impacts 30- and 90-day private-sector credit markets more than the expectations theory of the term structure predicts. The effect on public debt is smaller and statistically insignificant, implying that reserve supply shocks widen the gap between interest rates on public and private debt.

“The free market” and the Asian crisis

Abstract The Asian financial crisis, which devastated many of the newly industrializing countries, is said to have demonstrated the inherent fragility of economies built upon laissez‐faire principles. However, it appears that the major sources of disruption have come from policies that deviate from laissez faire, such as government‐guaranteed bailouts and international monetary policy. That capitalist economies were afflicted by the crisis does not constitute an indictment of free markets.