It's always refreshing to find someone who wants a good debate to be settled by experiment. Hopefully that would be enough. Portugal famously had great success with decriminalization of nearly all illicit drugs, but unfortunately I don't think too many countries have changed their own laws as a result. There's almost always too much politics involved, and it's usually easy to find a reason that is at least superficially convincing as to why what works elsewhere will not work at home.