Inputs, Incentives, and Complementarities in Education: Experimental Evidence from Tanzania*
在坦桑尼亚350所学校开展大规模随机实验，发现单独提供学校拨款对学生成绩无影响，教师激励有微弱正面效果，但两者结合效果显著大于各自效果之和，表明投入与激励存在互补性。
Abstract We present results from a large-scale randomized experiment across 350 schools in Tanzania that studied the impact of providing schools with (i) unconditional grants, (ii) teacher incentives based on student performance, and (iii) both of the above. After two years, we find (i) no impact on student test scores from providing school grants, (ii) some evidence of positive effects from teacher incentives, and (iii) significant positive effects from providing both programs. Most important, we find strong evidence of complementarities between the programs, with the effect of joint provision being significantly greater than the sum of the individual effects. Our results suggest that combining spending on school inputs (the default policy) with improved teacher incentives could substantially increase the cost-effectiveness of public spending on education.