Taxing video games will lower knife crime?

Well, according to some government adviser in the UK, yes. Is this a classic case of correlation and causation?

The "logic" goes like this: games are too cheap, so let's make them expensive, so kids won't become violent sociopaths. Yes, that makes sense. Perhaps the kids that commit the crimes are sociopaths in the first place?

Therefore, let's propose a government study where we randomly assign pools of kids that play violent video games and those that do something else like knit sweaters. Give them both access to knives and then set them free in a controlled playground and see if they start stabbing people.