The power of empirical evidence: assessing changes in public opinion on constitutional emergency provisions

Abstract The Japanese government is attempting to put emergency clauses in the Constitution. Although the overwhelming majority of legal scholars and practitioners vehemently oppose the initiative, public opinion polls indicate a close divide between opponents and supporters. This division may partly stem from the difficulty the public faces in reaching a conclusive decision through abstract legal arguments. Recently, an empirical study analyzing emergency clauses in various countries showed that such clauses tend to increase government violations of human rights and the death toll during disasters. Our survey experiment investigates how presenting such empirical evidence—which corroborates opponents’ legal arguments—as a treatment affects public support for the potential Japanese emergency clauses. We find that the treatment shifts the ratio of opposition to support from roughly 1:1 to 2.6:1. In the placebo group, the proportions of opposition, neutrality, and support are 28.8%, 43.2%, and 28.0%, compared to 47.7%, 33.6%, and 18.7% in the treatment group. Additionally, initial supporters of the clauses shift more toward opposition after the intervention than do opponents or neutrals. These results suggest that should a referendum be held, making the public aware of the empirical analysis could markedly influence the outcome.