Measuring the Chilling Effect

Supreme Court doctrine grants special protection against laws that “chill” protected speech, most prominently via the overbreadth doctrine. The overbreadth doctrine permits persons whose own speech is unprotected to challenge laws that infringe the protected speech of third parties. The Court has not generally applied overbreadth and the other speech-protective doctrines to other constitutional rights even though other rights could also be subject to a chilling effect. The case law simply assumes that the chilling effect only acts on the exercise of speech, and that this justifies treating speech differently from other rights.We tested these assumptions with respect to abortion rights. By comparing abortion rates with state laws over a two-decade-plus period, we found a statistically significant correlation between laws forbidding late-term abortions and the reduction of not only late-term but also “near-late-term” abortions, i.e., abortions in the roughly one month before the period in which abortions are forbidden. That effect persists even after controlling for potentially confounding variables, such as the number of abortion providers and pro-life public opinion. Moreover, the effect is not limited to the year of enactment or associated with failed policy initiatives, suggesting that the impact is due to the law itself rather than associated publicity. These findings are consistent with, and strongly suggestive of, a chilling effect on abortion providers and/or women seeking abortions. This result undermines the implicit assumption that the chilling effect is unique to laws regulating speech and vindicates the general proposition that laws can chill the exercise of constitutional rights beyond their literal coverage.