The Signaling Value of a High School Diploma
通过对比勉强通过和未通过高中毕业考试者的收入，发现文凭本身对收入几乎没有信号作用，从而区分了人力资本与信号理论。
This paper distinguishes between the human capital and signaling theories by estimating the earnings return to a high school diploma. Unlike most indicators of education (e.g., a year of school), a diploma is essentially a piece of paper and, hence, by itself cannot affect productivity. Any earnings return to holding a diploma must therefore reflect the diploma's signaling value. Using regression discontinuity methods to compare the earnings of workers who barely passed and barely failed high school exit exams--standardized tests that students must pass to earn a high school diploma--we find little evidence of diploma signaling effects.