Good night: Experimental evidence that nighttime curfews may fuel disease dynamics by increasing contact density.

Background: Nighttime curfews have been discussed and implemented in many countries as a means of controlling the COVID-19 pandemic. However, there is evidence that such curfews have little or no effect on disease dynamics when other measures such as bans on gatherings or business and school closures are already in place. There are two possible explanations for this. First, nighttime curfews may elicit reactance-a feeling of anger that drives non-adherence; second, nighttime curfews may motivate people to shift activities from night to daytime, thereby increasing contact density.

Methods: A survey experiment was conducted with German participants (N = 997) to investigate public perceptions of nighttime curfews and possible detrimental effects on contact behaviors.

Results: Most participants perceived nighttime curfews as ineffective. The introduction of a hypothetical curfew did not affect intentions to reduce private contacts but instead elicited reactance, motivating participants to violate curfew hours or to shift a fictitious dinner meeting to an earlier time rather than cancelling it.

Conclusions: When people do not support nighttime curfews or do not understand the rationale behind them, introduction of this measure may fuel the spread of the disease. For that reason, nighttime curfews should be a measure of last resort and should be accompanied by a public communication campaign explaining the importance of contact reduction during both nighttime and daylight hours.