The effect of face masks on Covid-19 transmission is crucial for the health of populations. The effectiveness of face masks in reducing the transmission of Covid-19 varies across primary evidence. To perform a quantitative meta-analysis, we collected 258 estimates from 44 primary studies...

In a recent working paper, Herby et al. conduct a systematic review and meta-analysis of the effects of lockdowns on COVID-19 mortality. Based on their results, they conclude that "lockdowns have had little to no public health effects" and that "lockdowns should be rejected out of hand as a...