Robert Dingwall, a Professor at Nottingham Trent University and a leading sociologist, has written an excellent piece for Social Science Space criticising the imposition of mask mandates, given the paucity of evidence that masks interrupt transmission and the lack of any robust evaluation of the harms masks cause.
First, Professor Dingwall looks at the two main sources of evidence purporting to show that masks are effective.
One is studies at various scales of the impact of mask mandates on reported infection rates. These may compare cities, states, provinces or entire nations using time series data to look for inflections of rates that may be attributable to the mandates. A great deal of mathematical ingenuity has been expended in trying to control for the numerous confounders from biases in reporting, differences in diagnosis, leads and lags in public behaviour in response to the mandates, seasonal fluctuations, mobility – the list is almost endless.
By the time these manipulations are complete, though, it is very difficult to conclude that there is any clear and obvious effect. Infection rates do not seem to vary much between comparable communities regardless of the NPIs that have been introduced. I have yet to see a study that identifies a clear and unequivocal benefit from a mask mandate in the form of an obvious inflection point attributable to the intervention. For all the reasons cited, this would be hard to find so perhaps we should not treat its absence as conclusive proof of a lack of benefit so much as something that is consistent with the RCT evidence that any benefit is likely to be minimal.