Edit: This plays into something I observe in most "data-driven" organizations. Having a statistic available about recovery costs makes it easy to shift the conversation toward that statistic, when you actually ought to be asking questions about (in this case) the causal impact of that intervention on the subway's overall profitability, the need for easily available public transit and whether there ought to be a fare in the first place, the public good (or maybe harm -- the point is that we ought to be discussing it one way or the other) done by using fare-jumping collections as a mechanism for training people to be less antisocial in other aspects of their lives, or whether that obscene cost of fare collection is actually a reasonable baseline and should be improved. Your statistic, while interesting, is almost useless when trying to figure out what we should do next, at least by itself, and when paired with human psychology it can be actively harmful.