Mixed evidence on effectivenss of wearing facemasks

Review of a few RCT that show weak to no evidence of effectiveness. Speculate on downsides as well

Third, at the microsocial level, the argument might be made that encouraging uptake of face masks might lead to reduced compliance with other measures, due to the false sense of security presented by the mask. Such arguments rest on evidence around risk compensation in other areas of public health, for example seatbelts, cycle helmets, vaccination against sexually transmitted infections, and injury prevention in competitive sports. ... [T]here is a case that face masks might promote, if not active risk-taking, then at least a complacency that might reduce adherence to other measures, especially given the largely collective rather than individual benefits that the wearing of masks seeks to address. ... There is also an argument that universal mask-wearing might aggravate the climate of fear already documented for Covid-19, 17 adding to mental health concerns by providing a constant reminder of the threat posed by other humans.