If you ever want to see a big, snarly, hairy fight, you can toss a squirrel into the middle of a dog park, or you can bring up the concept of punishment in a group of dog trainers. Dog trainers run the gamut from "no kind of unpleasant thing shall happen to a dog on my watch, ever" to "if you don't shove the dog around he'll shove you around, so you better shove harder." I have no desire to become the squirrel at the dog park, so I'm just going to put out a few things that we do know about punishment and then ponder how they might apply to our penitential system.
So, what do we know about punishment? Well, for one thing, it's only effective if it happens right after the offending behavior. If you turn a hose on your dog as it's fence-fighting with the neighbor dog, it might (might!) think better of it next time. If you come home and find that your dog has chewed a corner out of your drywall or eaten a sofa cushion, your yelling or smacking will have no effect whatsoever, except to make your dog wonder why you have suddenly turned into a raving and dangerous lunatic.
We know that, unlike rewards, punishments need to happen every time the offending behavior occurs in order to be effective. If you sometimes get doused for barking and snarling at the neighbor dog and sometimes you just get to carry on, most likely you're going to keep carrying on.
We also know that punishment, especially if not skillfully applied, can create unforeseen associations and resentments/fears. If you hit a dog (or a child), you probably expect them to come out thinking "That was unpleasant, I should never try that again!" However, they may just end up with an impression of "Ow! That was nasty. Apparently I can't trust you not to hurt me." You can also end up with weird phobias, like the horse that Temple Grandin (Animals in Translation) talks about who is terrified of people in black hats after being hurt by someone wearing a black hat. You don't always create the same negative associations you planned on.
So...how about that crime and punishment? Say that you have someone who is using illegal drugs. Say that this person gets caught. How close in time is the punishment likely to be to the offending behavior? (Actually, I have no idea. I don't even watch Cops. But I know that people go for quite some time awaiting trial.) Is the punishment likely to happen every time the offending behavior occurs? Not a chance in hell. This one I'm sure on. Is putting this drug user in jail likely to create unintended negative consequences? It certainly wouldn't surprise me. I'm just kind of guessing that your average prison inmate doesn't spend most of their time reflecting on how prison is a logical consequence for their poor choices, and how they will never make such poor choices again. I could be wrong, but I'm kinda guessing that inmates are much more likely to be resentful of people in authority than otherwise. Not to mention that what small-time offenders are likely to learn from spending time with bigger-time offenders is hardly likely to be the kind of education you were hoping to sponsor.
Now, I'm not saying that we should abolish prisons. There are some folks who are simply too dangerous to have walking around, and they need to be contained. There's a difference between teaching and management. If your dog bites, put a muzzle on it before you go out in public. But the number of pathological serial killers/serial rapists, etc. has got to be vanishingly small compared to the number of people in prison. If prison doesn't work as punishment (punishment being defined as something that reduces a behavior) then aren't we spending a whole lot of money on something that simply doesn't work? (See here for one of many articles indicating that this is, in fact, the case.)
Nobody has asked my opinion on how to solve California's many-billion dollar budget deficit, but here is my modest proposal. Let everybody who isn't dangerous out of jail. Legalize drugs, since punishing people for taking them simply isn't keeping people from taking (or selling or producing) them. Have clear labels on all drugs indicating how dangerous they are, and levy high taxes. Use those taxes for drug treatment and prevention programs, and for public education programs about the hazards of drug use. These changes will, and the very least, save us many billions of dollars, and will probably result in lower rates of drug use.
Here's my question for politicians (and the people who vote for them) who are "tough on crime": does tough on crime mean "finding and implementing the most efficient possible ways to reduce crime" or does it mean "make people who commit crimes suffer"? Personally, I'd rather that we used the best information we have to get the best results, rather than assuming that our main goal should be to look as tough and snarly as possible. But hey, maybe I'm just the squirrel at the dog park....