THE nation's prison population grew 2.6 percent last year, the largest increase since 1999, according to a study by the Justice Department. The jump came despite a small decline in serious crime in 2002. It also came when a growing number of states facing large budget deficits have begun trying to reduce prison costs by easing tough sentencing laws passed in the 1990's, thereby decreasing the number of inmates. Advertisement

"The key finding in the report is this growth, which is somewhat surprising in its size after several years of relative stability in the prison population," said Allen J. Beck, an author of the report. Mr. Beck is the chief prison demographer for the Bureau of Justice Statistics, the statistical arm of the Justice Department, which releases an annual study of the number of people incarcerated in the United States.

At the end of 2002, there were 2,166,260 Americans in local jails, state and federal prisons and juvenile detention facilities, the report found.

Another important finding was that 10.4 percent of black men ages 25 to 29, or 442,300 people, were in prison last year. By comparison, 2.4 percent of Hispanic men and 1.2 percent of white men in the same age group were in prison.

The report, which was released yesterday, found that this large racial disparity had not increased in the past decade. But Marc Mauer, the assistant director of the Sentencing Project, a prison change research and advocacy group, said that with the number of young black men in prison remaining so high, "the ripple effect on their communities, and on the next generation of kids growing up with their fathers in prison, will certainly be with us for at least a generation."

Mr. Beck, Mr. Mauer and other experts said the growth in the prison population last year, despite the efforts by some states to reduce the number of inmates, was a result of the continuing effect of draconian sentencing laws passed in the 1990's when the states could afford to build more prisons and politicians competed to sound tough on crime.

Mr. Beck said increases in inmates in several of the largest states contributed to most of the national increase. Those states included California, Florida, Michigan and Pennsylvania, he said. In Florida, he said, local judges used their discretion under the tougher laws to sentence more people convicted of felonies to prison rather than probation or some other program.

Alfred Blumstein, a leading criminologist at Carnegie Mellon University, said it was not illogical for the prison population to go up even when the crime rate goes down.

For one thing, Professor Blumstein said, some crimes considered victimless are not counted in the Federal Bureau of Investigation's annual report on the crime rate, including drug crimes, gun possession crimes and immigration offenses.

Another reason, Professor Blumstein said, was that it has become increasingly clear from statistical research that "there is no reason that the prison count and the crime rate have to be consistent." The crime rate measures the amount of crime people are suffering from, he said, while the prison count is a measure of how severely society chooses to deal with crime, which varies from time to time.

Mr. Beck said he did not believe the sizeable increase in the prison population last year was the start of a trend back to the big increases of the 1980's and 1990's, when the number of incarcerated Americans quadrupled. States do not have the money to build more prisons now, he said, and the push by a number of states to reduce inmate populations will have some effect on the numbers.

Among the states that have eased sentencing laws in the past year are Michigan, which scrapped mandatory minimum sentences for drug offenses, and Kansas, Texas and Washington. Several states, including Kansas and California, have new laws mandating drug treatment rather than prison for nonviolent drug offenses.

Although many advocates of prison change have blamed drug arrests for the significant growth in the prison population, the report found violent crimes responsible for 64 percent of the increase in the number of men in state prisons from 1995 to 2001. Violent crimes also accounted for 49 percent of the increase in the number of women in state prisons in those years. Professor Blumstein said that figure was unusual because women have generally been convicted of drug and property crimes.

In total, 49 percent of inmates in state prisons last year were serving time for violent crimes, the report said. Twenty percent were serving time for drug offenses, 19 percent for property crimes, and 11 percent for public-order offenses, like drunken driving, parole violations and contempt of court.

But in the federal prison system, which with 163,528 inmates is now larger than any state system, 48 percent of the growth in the number of prisoners from 1995 to 2001 was accounted for by drug crimes and only 9 percent by violent crimes.

The number of inmates in federal prisons for gun crimes increased by 68 percent from 1995 to 2001, as Congress, President Bill Clinton and President Bush pushed to federalize some illegal gun possession cases.

In addition to 1.4 million Americans in state and federal prisons in 2002, 665,475 people were in local and county jails and 110,284 were in juvenile facilities, the report said.

California had the largest number of inmates, with 162,317 followed closely by Texas, with 162,003.

Louisiana had the highest rate of incarceration, with 794 inmates per 100,000 residents. Maine and Minnesota tied for the lowest incarceration rate, with 141 inmates per 100,000 residents.

Copyright 2003 The New York Times Company. Reprinted from The New York Times, National, of July 28, 2003.