Local police pay for themselves in traffic and parking tickets, among other fees. So maybe we should keep adding cops until we've maximized fine revenue.
Or maybe marginal profit isn't a good way to measure law enforcement...
The question is, is this analogous to paying taxes? Perhaps to some extent—there are most likely enough uncollected taxes that discrimination in enforcement could be an issue, for instance. Although I expect that at the current level of enforcement, more investment would reduce that problem rather than exacerbate it. But more generally, do we see 'minor' tax cheating as being analogous to driving 1mph over the speed limit? I'm not so sure. Certainly the consequences should be proportional to the crime: small and accidental underpayments should simply result in having to pay the amount owed. But it seems to me that people (and corporations) should be required to pay all taxes legally owed, so over-enforcement in this area shouldn't be a concern until it got to the level where money was being spent that could be better used elsewhere. (Which obviously isn't the case when you're seeing a marginal profit on enforcement.)
I suppose the logical counter-argument would be that the money could be better spent by the people earning it in the first place—IE that taxes should be lower—and indeed I do expect this is the belief of most people who argue against enforcement.
I think laws should be simple and enforced. For example, raise speed limits so they are high enough that nobody has a reason to routinely break them, then draconian enforcement. Old white Grandpa weaving around should get the same penalty as young Black guy weaving through traffic.
