It costs the City of New York about $170 a day for each prisoner in the custody of the city’s Department of Corrections. That cost includes wages for the city’s unionized correction officers, along with meals, uniforms and health care for the prisoners. If you take the city corrections department’s an nual budget and divide it by the number of prisoners and the number of days in a year, that’s the number you get.

It costs Cook County, Illinois, which runs the jail for Chicago, $43 a day for each prisoner. It costs Los Angeles County, which runs the jail for L.A., $49 a day.

To get a sense of the scale of the inefficiencies at work here, consider how many people it takes Cook County to guard its roughly 11,000 inmates: 3,000. And then consider the size of the staff of the New York City De partment of Corrections, which has an inmate population of about 14,000: 12,000. In other words, it’s taking New York four times as many employees to take care of fewer than one and a half times as many inmates.

It’s not as if the Cook County jail is some marvel of modern technology and efficiency, either. The oldest building in the complex dates to 1929, and it is staffed by members of public employee unions like the American Federation of State, County and Municipal Employees. Why can Chicago jail prisoners for so much less than New York can? “I wouldn’t even want to venture a guess,” says a spokeswoman for the Cook County Department of Corrections, Joan Stockmal.

Well, we’ll hazard a guess: it may just have something to do with New York City’s political culture. It’s a culture in which politicians from both parties — Mayor Bloomberg, a Republican, and Council Speaker Miller, a Democrat — are asserting that the city can’t bridge a $6 billion gap in its $42 billion budget without resorting to massive tax increases. The budget just can’t be balanced by cutting, the politicians insist.

No economic difficulties would be severe enough to justify keeping prisoners in cruel or slovenly conditions. No matter how serious their crimes, convicted criminals deserve to be incarcerated in an environment free from rape or other abuses. But it takes some nerve for the politicians to go to the public and seek a tax increase when the politicians are presiding over a correction system that is fully three times as expensive as comparable systems in other cities.

Our impulse in these cases is to turn to the private sector. The job of running the city’s jails could be opened up for bidding to private companies. The Reason Public Policy Institute reports that on average private prisons are between 10% and 15% less costly than publicly run ones are. We checked in with one such company, Corrections Corporation of America, which runs jails in Florida, Oklahoma, and Nashville. A spokesman for that company, Steven Owens, told The New York Sun that if New York City were to put its corrections work out to bid, “we would certainly take a look.”

Defenders of New York’s status quo will be ready with scare stories about conditions in other jails: violence, escapes, race riots. But scare stories are exactly what those are. They will be ready, too, with excuses about how court orders and consent decrees govern everything down to the temperature of the food served to the inmates. But excuses are exactly what those are.

Be prepared, too, for explanations of why New York is different from L.A., where sheriff’s deputies serve stints both as the police officers that patrol unincorporated areas outside the city of Los Angeles and as the jail guards. But these aren’t good reasons for New York to go on overpaying. Instead, they are arguments for allowing New York’s Police Department to take over the Corrections Department.

The other big excuse that will get raised by those opposed to correcting the city’s corrections department is a state law, assembly bill 6038 of 2002, requiring that, as Governor Pataki put it, “the duty of maintaining the custody and supervision of persons detained or confined by the Department of Correction of the City of New York be performed solely by members of the uniformed force of the City Department of Correction.” In a recent message on the topic, Mr. Pataki assured New Yorkers that he remains “opposed to privatizing the ownership or operation of state and local correctional facilities.”

That position helped win Mr. Pataki the endorsement of the labor unions that represent correction officers in New York State and New York City. But it’s also part of the reason our jails are so costly. If the Republican governor is willing to remove even the threat of privatization, why should the politicians and bureaucrats and unions even bother to seek savings?

If New York City could cut its jail costs to a level roughly on par with Chicago’s or Los Angeles’s — to, say, $50 an inmate a day — the city’s corrections department budget would be reduced to $256 million from the present level of about $850 million. That’s a savings of $594 million a year. That’s 594 million more reasons to doubt the politicians when they say a tax increase is needed.