The government can meddle in your life both via both your production and consumption. That is, it can tell you how much of what to produce, and how to do that, and it can tell you how much of what to consume, and how to do that. These meddlings can be general and uniform across the population, and decided by a legislature. Or they can make more distinctions between people, and be decided by low level government employees.
For example, the government can subsidize fresh fruits and vegetables in general, for everyone, or Ms. Jones’ social worker might tell her that if she wants to keep her kids she better serve more fresh spinach to her children at dinner this week. The government can require everyone to pay the same fraction of their income in taxes, or a draft board can choose to conscript Mr. Jones into becoming a solider, and then his sargent can order him to take that hill now.
While we might disagree on where we would draw the line, I think we can all agree that, all else equal, it is better if the government decides at a high level to meddle uniformly in everyone’s lives, than if low level government employees meddle very specifically in particular details of individual lives. While an unregulated society most likely does have market failures that legislatures can mitigate via general rules, it is harder to believe that low level employees know enough about particular people to meddle well in their details. Furthermore, detailed meddling allows more corruption and arrogance by officials, and induces more hurt pride and resistance by those controlled.
We can, I think, go further and agree that it seems harder to justify meddling in production, relative to consumption. For example, we may accept the government using a general rule to tell us how much we owe in taxes, but it seems harder to accept a government official telling us in particular what kind of career to go into, what job to take, or whether we must work this Saturday. Regulations about job safety, for example, work better as general rules that apply to all jobs, rather than being chosen at the discretion of a particular official regarding a particular workplace.
I propose that we all think about law vouching in this context. Just as a government who decides how much you owe in taxes does not decide how you acquire that money, a government who decides that you owe a legal debt due to a crime you’ve committed need not be empowered to decide how you pay that debt, if that you will in fact pay that debt.
In our world today, the judge who sentences a criminal not only decides the overall level of their “debt owed to society”, but also specifies the particular kind of punishment. Usually prison, but sometimes fines or community service. (And in the past: public shaming, torture, exile, or death.). And our governments and courts regulate those prisons in great detail. Even so, prisons are terribly expensive and yet not very effective at deterring crime. And as you leave prison, your parole board and officer will make many detailed decisions on how you can live your life.
Under vouching, there is no government parole officer and the judge would instead only specify the fine your owe, which would be paid by your voucher. (And could depend on your wealth.) Then you would be further punished according to your prior contract with your voucher. You and your voucher would also choose your privacy rights and freedoms of actions, and suffer larger fines if those make it harder to catch and convict your crimes. Furthermore, you and some close friends could together choose co-liability, to show you will watch each other.
Under vouching, you would repay your debt to society, and be in much more in control of how to repay that debt. Just as with tax debts now. Does anyone really think that judges, police, or prison officials are extra good at deciding what will deter crime in any one individual? Moreso than all the other government officials who we do not let dictate the details of our lives?
Not that I’m not pushing for some extreme libertopia where government has no powers. I’m instead appealing to a quite common feeling that government meddling should be limited and general; our default should be to avoid it, when possible.
I would consider retribution to be of low value and not worth for policymakers to consider (and you might argue, like Robin, that on some level retribution is also "really" about deterrence). All three other are about harm reduction which is generally considered to be the main aim of criminal justice system. If e.g. long prison sentences are ineffective at that then it might be a good reason to look for a different kind of policy.
We normally say that there are four major categories of justification for punishment:* Deterrence * Retribution* Incapacitation* Rehabilitation
Deterrence is far from the only reason that people give, and I am surprised that you imagine so.