Comment by DangitBobby

The null hypothesis could just as easily be if they get a 1:1 dollar exchange rate versus a 1:2 rate on their food stamps, they can afford to buy drugs AND food instead of just drugs. Guess which one they buy if they can only buy one? Guess what they are incentivized to do if they have less cash than they need on hand to do both? I'll give you a hint, it rhymes with teal.