Do you have any idea how silly you look, demanding to see hard evidence before changing your mind?
1) Please explain to me, in simple language, just where in the U.S. of A. there is going to be any chance of such an experiment going on? I am quite sure that any evidence from elsewhere will be discounted as irrelevant, and lobbied against if there is a whiff of a chance some politician might take it seriously. After all, Canada is sure getting a fair bit of arm-twisting over the mere possibility that possession of small amounts of marijuana will be decriminalized (not legalized, I would like you to carefully note, decriminalized). And you are demanding multiple studies.
2) It took only the most cursory of web searches for me to find this study. A baby step, of course, but a start.