Crime is not just another policy issue on par with unemployment or gay rights. Suppression of crime is a sine qua non for civilization. Serious crimes in the United States exploded during the 1960s and 1970s, leveled off in 1980s and declined in the 1990s; although the rate of serious crime (violent crimes plus burglary) still remains three times higher than it was in 1960. A majority of Americans will become victims of a serious crime over their lifetimes.

Why? Primarily because the justice system became unbelievably soft on criminals in the 1960s and stayed that way until recently. The central idea of a successful criminal justice system is to afflict the guilty and leave the innocent unmolested. As Adam Smith wrote nearly two and a half centuries ago, "Kindness toward the guilty is cruelty toward the innocent." The social harm done by the criminal must be reflected back onto him so that he makes no mistake about the harm he is doing. Bad decision; bad consequences.

Expected punishment

Perhaps the best single way to capture the effectiveness of the justice system is the number of prison days served per serious crime reported to the police. This measure, called "expected punishment," nicely rolls the chances of being arrested, prosecuted, convicted and the number of days likely to be served in prison into a single number.

Between 1950 and 1980 the expected punishment for crimes of violence and burglary fell by 80 percent from seven weeks to 10 days. Expected punishment for robbery, for example, went from 140 days in 1950 to 34 days in 1980. Gee, I wonder why crime mushroomed? The chances of going to prison for a serious crime collapsed from 5.3 percent in 1950 to 1.6 percent in 1980.

The essence of deterrence is credibility

Expected punishment remained low into the early 1980s because although the chances of going to prison increased, this was offset by shorter sojourns in crowded prisons. Then expected punishment began to rise a decade ago and gradually rose to nearly 20 days per crime. Even so, expected punishment is only about half of what it was 40 years ago.

What needs to be done? The essence of deterrence is credibility and the courts may be in the process of recovering it. The myth is that "getting tough" just won't work. Yet common sense and a raft of serious studies suggest otherwise.

Here are four things that would strengthen external restraints on criminals:

• Abolish the juvenile justice system. Stop seducing youths into a life of crime. Equal justice for all. As Wisconsin Judge Ralph Adam Fine pointedly says, "We keep our hands out of a flame because it hurt the very first time (not the second, fifth or tenth time) we touched fire."

• Repeal the Miranda ruling. The most famous Supreme Court criminal decision was egregiously in error and very damaging. Ordering the police to do all they can to discourage suspects from making perfectly voluntary statements has reduced confessions by about 25 percent and permanently depressed arrest clearance rates by 25 percent as well.

• Restore "shaming sentences" -- degradation, the stocks, the pillory and flogging. I'm not kidding. Probability, immediacy and type of punishment are more important than the longer and longer sentences in air conditioned prisons currently favored to discourage crime. Corporal punishment is constitutional (the fifth amendment implies it), efficient, effective and egalitarian.

• Privatize parts of the justice system on a piecemeal basis. Only competition and market-driven reforms can improve things; not more tax money poured into bureaucratic monopolies. For example, we can effectively privatize the parole and probation systems by requiring those eligible to post a private bond, payable on the installment plan, financially guaranteeing their good behavior. Violations would result in financial losses for the convict and his co-signers.

Steps like these would go a long way to lowering the crime rate. They would be good for our society.