中文摘要
兼职副业在经合组织国家日益流行，5% 至 10% 的劳动者同时持有两份或以上工作。然而，由于缺乏识别性变异，人们对兼职副业对财务激励的反应程度知之甚少。本文研究德国一项独特改革，该改革允许劳动者免税从事小规模第二职业，使边际税率下降 19.5 至 66 个百分点。研究表明，该改革导致兼职副业急剧增加，且这一增加并未被主要收入的减少所抵消，同时工时约束是兼职副业的关键决定因素。(JEL H24, H31, J22, J31)
Abstract
Moonlighting is increasingly popular in OECD countries, with 5 to 10 percent of workers holding two or more jobs. However, little is known about the responsiveness of moonlighting to financial incentives due to the lack of identifying variation. This paper studies a unique reform in Germany that allowed workers to hold small secondary jobs tax-free, decreasing the marginal tax rate by between 19.5 to 66 pp. I show that the reform resulted in a dramatic increase in moonlighting that was not offset by reductions in primary earnings and that hours constraints are a key determinant of moonlighting. (JEL H24, H31, J22, J31)