A recent meta-analysis by three economists, commonly, if misleadingly, referred to as the Johns Hopkins study, suggested that lockdowns had little to no effect on Covid-19 mortality. Critics accused the authors of ideological bias in interpreting, or even manipulating the evidence to fit their pre-existing beliefs.  One might think that by this point, figuring out the effectiveness of lockdowns would be a simple matter of looking at the data, the facts. But while the question might seem like a purely empirical one, it’s not, argue Lucie White and Philippe van Basshuysen.