Equal, Yet Unequal
We typically deter crime via a chance of punishment. Someone who commits a crime might get found out, prosecuted, convicted, and sentenced. So the amount of deterrence should increase with the chance of that sentence give committing a crime, with the size of the punishment implied by the sentence, and with the delay in that punishment relative to when the crime was committed.
We currently let people pay more to increase the chance of punishment for crimes where they are the victim. For example, they can hire a private investigator, pay snitches to talk, or install cameras to give more info to investigators.
We could in principle also let individuals pay to increase punishment levels. For example, if the federal sentencing guidelines said that a particular crime should be punished by 41-51 months in prison, we might let each person pay so much per month to increase those levels. Such people might might announce such new levels in an attempt to especially deter crime against them personally. Just as they now try to publicly show that they have paid for cameras, etc.
But note, many would be outraged by such a policy, and we don’t actually allow this. That is, we let people pay to influence the chance but not the level of punishment, even though the chance matters at least as much as level for deterrence. We could forbid many of the ways that people increase punishment chances, but we don’t. Why?
My guess: we often like the appearance more than the substance of equality. So we want to have some things we can point to and say “see, we treat everyone equal”, as long as there are other less noticeable parameters where we can more freely pay to make things unequal.
Note that we allow city mayors to do something similar. A city mayor can typically instruct the police to invest different levels of police resources into different neighborhoods, in effect making the chances of getting caught vary greatly by neighborhood. But we wouldn’t let mayors set levels of punishments given a conviction differently for different neighborhoods; that would be unacceptably overt inequality.
As another example, consider that in legal trials we don’t let you pay the judge to lean their decision toward you, or pay for better trial rules of evidence, or for more time to present your case. Or to stand closer to the jury when talking to them. But we do let you pay for a better lawyer, which most people see as making a big difference to getting more favorable rulings. We could assign trial participants to get random lawyers, but we don’t. Again, we are proud to highlight some dimensions on which we insist on equality, refusing to let people pay for advantages, but on other similarly influential dimensions we do let you pay.
There are probably many more related examples; please do share them in the comments.