Five Things About Deterrence:

1. The certainty of being caught is a vastly more powerful deterrent than the punishment.

Research shows clearly that the chance of being caught is a vastly more effective deterrent than even draconian punishment.

2. Sending an individual convicted of a crime to prison isn’t a very effective way to deter crime.

Prisons are good for punishing criminals and keeping them off the street, but prison sentences (particularly long sentences) are unlikely to deter future crime. Prisons actually may have the opposite effect: Inmates learn more effective crime strategies from each other, and time spent in prison may desensitize many to the threat of future imprisonment.

3. Police deter crime by increasing the perception that criminals will be caught and punished.

The police deter crime when they do things that strengthen a criminal’s perception of the certainty of being caught. Strategies that use the police as “sentinels,” such as hot spots policing, are particularly effective. A criminal’s behavior is more likely to be influenced by seeing a police officer with handcuffs and a radio than by a new law increasing penalties.

4. Increasing the severity of punishment does little to deter crime.

Laws and policies designed to deter crime by focusing mainly on increasing the severity of punishment are ineffective partly because criminals know little about the sanctions for specific crimes.

More severe punishments do not “chasten” individuals convicted of crimes, and prisons may exacerbate recidivism.

See Understanding the Relationship Between Sentencing and Deterrence [1] for additional discussion on prison as an ineffective deterrent.

5. There is no proof that the death penalty deters criminals.

According to the National Academy of Sciences, "Research on the deterrent effect of capital punishment is uninformative about whether capital punishment increases, decreases, or has no effect on homicide rates."

[1] https://nij.gov/five-things/Pages/deterrence.aspx#addenda

I feel like the whole "being locked in a building for a couple years" thing is already a huge deterrent.

Because of that alone, it's likely you'll lose your job, your house, almost all your possessions.

I feel like most stuff on top of that doesn't really change the calculus too much, because even being locked in the nicest prison in the world is not great for an average person.

(Rich people it's a bit different because they have the resources to handle this)

The evidence seems to indicate that harsher sentences have barely any effect on crime deterrence: https://www.economist.com/blogs/freeexchange/2016/03/crimina...

It actually tends to be counterproductive. If you shit on people enough and there is no upside to cooperating, people just become increasingly subversive, often with tacit support from otherwise law abiding citizens.

The US has a track record of punishing people of color disproportionately. We have the term jury nullification to describe one means for ordinary people to engage in peaceful non cooperation. During Prohibition, lots of ordinary people looked the other way so the mafia could make alcohol available. It basically gave money and power to the mob to make alcohol illegal. In Asia, Martial Arts were born due to extremes of laws forbidding people from having weapons.

The more unreasonable the government becomes, the more creative the people get in quietly saying "Fuck you. No." Or they eventually outright rebel. The first thing that happens when a government is overthrown is they empty the prisons on the assumption that most prisoners are really political prisoners, regardless of what they were convicted of.

Apparently not enough of a deterrent to keep our prisons from over crowding. It is also inhumane in my opinion. I think that it would do everyone well to spend a weekend in solitary in jail. It is torture and should be seen as such.

How does denying people the ability to work amount to a deterrent? If anything, it has the opposite effect; if you cannot work legally after being released from prison, how can you possibly live a normal life?

If only people in jail know how bad it is and it makes them more likely to commit more crimes then it's got the opposite effect. What you're talking about is the reputation which has little to do with the reality. We could for example use propaganda like movies to make prison seem worse without actually making it suck that bad.

Unfortunately I don't have a source, but as I understand it, there are three important factors for effective punishment (as a deterrent and to prevent recurrence). Namely, that punishment should be certain, immediate, and proportionate. The criminal justice/carceral system of the United States achieves none of these.

It's much more effective to have small, immediate certain punishments than disproportionately large punishments in a small fraction of cases. One reason for this is that humans are not good at estimating expected values, and vastly underestimate low probabilities.