I don't feel comfortable with people just claiming that there's a positive ROI, but I feel the same about claiming "usually the ROI doesn’t materialize for the

I don't feel comfortable with people just claiming that there's a positive ROI, but I feel the same about claiming "usually the ROI doesn’t materialize for the State" without anything to back it up. >The history of these things is overwhelmingly that in the final tally, actual benefits fall far short of break even. Do you have some source for this?