What do you mean this is a perfectly valid statistical method to employ. It's being used in all sorts of contexts, e.g. violent crime, men are X times more li

What do you mean this is a perfectly valid statistical method to employ. It's being used in all sorts of contexts, e.g. violent crime, men are X times more likely to commit violent crime. That number comes from instances of violent crime and then you related the percentage of instances committed by men to the percentage of men in the population. That's the exact same methodology, except here in this study they use the control group to find what the average size of a public corporation is.