When jobs offered by different employers are not perfect substitutes in the minds of workers, employers gain wage-setting power; the extent of this power can be captured by the elasticity of labor supply that each employer faces. Estimates of this parameter reported by the literature vary...

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...