COLUMN RIGHT : It’s Safe Streets Versus Urban Terror : In the ‘50s, rampant crime didn’t exist because offenders feared what the police would do.

If you offer a small boy one candy bar now or 10 tomorrow, he’ll grab the one. That’s because children have what economists call a “high time preference.” They want it, and they want it now. The future is a haze.

The punishing of children must take this into account. One good whack on the bottom can have an effect. A threat about no TV all next year will not.

As we grow older, this changes. We care more, and think more, about the future. In fact, this is the very process of maturation. We plan, save, invest and put off today’s gratification until tomorrow.

But street criminals, as economist Murray N. Rothbard points out, have the time preference of depraved infants. The prospect of a jail sentence 12 months from now has virtually no effect.

As recently as the 1950s--when street crime was not rampant in America--the police always operated on this principle: No matter the vagaries of the court system, a mugger or rapist knew he faced a trouncing--proportionate to the offense and the offender--in the back of the paddy wagon, and maybe even a repeat performance at the station house. As a result, criminals were terrified of the cops, and our streets were safe.

Today’s criminals know that they probably won’t be convicted, and that if the are, they face a short sentence--someday. The result is city terrorism, though we are seldom shown videos of old people being mugged, women being raped, gangs shooting drivers at random or store clerks having their throats slit.

What we do see, over and over again, is the tape of some Los Angeles-area cops giving the what-for to an ex-con. It is not a pleasant sight, of course; neither is cancer surgery.

Did they hit him too many times? Sure, but that’s not the issue: It’s safe streets versus urban terror, and why we have moved from one to the other.

Liberals talk about banning guns. As a libertarian, I can’t agree. I am, however, beginning to wonder about video cameras.