> If the measurement is based on sales there will also be an obvious increase after legalization as the majority of sales are recorded.

This may be true, but it’s the best measuring that we have. I don’t know if it’s worth throwing out the existing measures we have from before and after legalization on a hunch that it might be different results. The surveys try to account for this as much as they can.

I agree that people shouldn’t be punished for their drug use, but I think the point is that without punishment, drug use increases. And there are some negative impact from that increase.