I can't read the article due to the the paywall, but any halfway decent study should be attempting to control for these things. Propensity score matching, or si

I can't read the article due to the the paywall, but any halfway decent study should be attempting to control for these things. Propensity score matching, or simply including these factors in a regression model should help remove some of the effects. Obviously, there is potentially an unlimited number of possible cofounders, and therefore the assumption that they've all been accounted for should always be met with skepticism, and is why the mantra "correlation is not causation" is so often repeated. If a modern research paper cited by the Economist has failed to even account for some of the potential confounding here, then I have great concerns for the future of science.