中文摘要
电子监控（EM）已成为遏制庞大监狱人口增长的一种流行工具。然而，关于电子监控对再次犯罪的因果效应，现有证据有限，且这种监禁替代措施如何影响违法者的劳动供给及其家庭成员的结果尚不明确。我们研究了瑞典1997年在全国范围内推行的电子监控扩张改革，该改革允许被判处不超过三个月监禁的违法者选择以电子监控替代监禁。我们的双重差分估计将处理组违法者入狱流入率的变化与刑期略长的未处理组违法者进行比较，结果表明该改革显著减少了监禁人数。我们的主要发现是，电子监控不仅降低了再次犯罪率，还增加了劳动供给。此外，电子监控还提高了受该改革影响父母的子女的教育成就和早年收入。电子监控发挥作用的主要机制似乎在于维系违法者与劳动力市场的联系，即通过降低求职和更换雇主的障碍来实现。我们的计算表明，电子监控带来的社会效益约为因监狱支出减少而节省的财政开支的七倍，这意味着电子监控带来的福利增益可能远高于以往的认识。
Abstract
Electronic monitoring (EM) has emerged as a popular tool for curbing the growth of large prison populations. Evidence on the causal effects of EM on criminal recidivism is, however, limited and it is unclear how this alternative to incarceration affects the labor supply of offenders and the outcomes of their family members. We study the countrywide expansion of EM in Sweden in 1997 wherein offenders sentenced to up to three months in prison were granted the option to substitute incarceration with EM. Our difference-in-differences estimates, which compare the change in the prison inflow rate of treated offenders to that of non-treated offenders with slightly longer sentences, show that the reform significantly decreased the number of incarcerations. Our main finding is that EM not only lowers criminal recidivism but also increases labor supply. Additionally, EM improves the educational attainment and early-life earnings of the children whose parents were exposed to the reform. The primary mechanisms through which EM operates appear to involve the preservation of offenders’ ties to the labor market, by reducing the barriers to both finding a job and changing employers. Our calculations suggest that the social benefits stemming from EM are about seven times larger than the fiscal savings associated with reduced prison expenditures, implying that the welfare gains from EM could be much greater than previously acknowledged.