The Rikers Island correctional complex, which costs New York City hundreds of millions of dollars annually to run. Emmanuel Dunand/AFP/Getty Images

A recent report found that jailing an inmate in New York City for one year costs more than four years of tuition at an Ivy League university.

The Independent Budget Office found that in 2012 it cost the city $167,731 to hold each of its daily average of 12,287 inmates, or about $460 per inmate per day.

Undergraduate tuition at Harvard University is $38,891 annually, or $155,564 for a four-year degree.

Of those inmates, more than 2,000 were being held for drug offenses, surpassing the number for murders or robberies.

The majority of inmates are African-American (57 percent), followed by Hispanics (33 percent), whites (7 percent) and Asians (1 percent), a New York City Department of Corrections report said. The majority of inmates come from less affluent areas of the city.

Experts say certain expensive fixed costs in New York's system keep the figure high despite a large drop in incarceration, which peaked in 1991 at about 22,000 inmates. The Department of Corrections has substantial pension and salary responsibilities and significant debt-service payments. It says 86 percent of its operating costs go to wages; it employs 9,000 relatively well-paid unionized correction officers. The department's budget in 2012 was $1.08 billion.

Hundreds of millions of dollars are spent each year to run Rikers Island — a 400-acre island near the runways of LaGuardia Airport that has 10 jail facilities, thousands of staff members, its own power plant and a transportation system.

New York's per-inmate costs dwarf other large cities'. Los Angeles spent $128.94 per day, or $47,063 per year, in its 2011-12 fiscal year, LA's sheriff's office said. According to the Cook County Sheriff's Office, in 2010, the most recent year for which figures were available, Chicago spent $145 per inmate per day, or $52,925 for the year.