Skills, Schooling, and Household Income in Ghana
利用加纳的数学和英语测试分数衡量认知技能，估计其对家庭总收入、农业收入和非农收入的影响，发现认知技能显著提升总和非农收入，但对农业收入影响不显著。
This article examines the impact of cognitive skills on the income of households in Ghana. It uses scores on mathematics and English tests to measure cognitive skills and estimates the returns to these skills based on farm profit, off-farm income, and total income. The article uses Powell's censored least absolute deviations and symmetrically trimmed least squares estimators to estimate farm and off-farm income. In contrast to Heckman's two-step or the Tobit estimator, Powell's estimators are consistent in the presence of heteroscedasticity and are robust to other violations of normality. The results show that cognitive skills have a positive effect on total and off-farm income but do not have a statistically significant effect on farm income.