WASHINGTON -- America's prison population has exploded since 1980, growing by almost 134 percent to a total of 771,000 inmates, the government reported.
The increase can be explained by the problem of illegal drugs and a higher likelihood that an arrest will result in a prison term, officials said Wednesday.
The number of state and federal prisoners grew 8.2 percent last year, the Justice Department said, a reduction in the growth rate during 1989 of 13.5 percent.
But during the 1980s, the nation's prison population increased by almost 134 percent.
At the end of 1980, there were almost 330,000 convicts in America's state and federal prisons. That number exploded to 771,000 at the end of 1990.
'Prison population has also been affected by changes in the extent of the illegal drug problem,' the Bureau of Justice Statistics said in a report.
'An estimated two-thirds of those in state prisons for a drug offenses were convicted of trafficking or manufacturing illegal drugs,' the Justice Department agency reported. 'Since 1985, the number of adult arrests for drug violations has increased by 74 percent and the number of arrests for sales or manufacturing of illegal drugs has grown by 137 percent.'
An arrest also was more likely to lead to a prison term, the statistics showed.
'There is some evidence that ... changes in criminal justice policies have increased a criminal's probability of being incarcerated from levels existing in prior years,' the study said. 'Murder, non- negligent manslaughter, rape, robbery, aggravated assault and burglary are among the most serious crimes and account for approximately half of prison commitments from courts.'
In 1960, there were 62 'prison commitments' for every 1,000 of those crimes reported to authorities. The ratio began to decline steadily in the 1960s and was relatively stable during the 1970s. But during the 1980s, the ratio rose from 25 'commitments' per 1,000 reported crimes to 62 'commitments.'
It is expensive to house prisoners and the cost keeps rising.
In 1990 alone, almost 60,000 new convicts entered the prison system. Such an increase in the incarceration level requires some 1,100 new prison beds every week.
Each new prison bed costs an estimated $50,000 in construction expenses alone, expert said. Then taxpayers must shell out another $12, 000 a year to feed each prisoner.
'We estimate from what the prison authorities reported to us that prisons throughout the country were operating at 18 to 29 percent above their capacities,' said Steven Dillingham, director of the Bureau of Justice Statistics.
Other highlights of the report:
--For the first time since 1981, the increase in male prisoners in 1990 exceeded the increase for women. The number of male prisoners rose 8.3 percent and the number of female prisoners grew by 7.9 percent.
--California had the largest increase in the number of prisoners. The number of convicts rose 11.5 percent -- some 10,000 men and women.
--Thirteen states and the federal system experienced increases of at least 10 percent in the number of prisoners last year. Vermont recorded a 15.9 percent increase, Washington state rose by 15.4 percent and New Hampshire by 15.1 percent.
--State prison populations rose by 8 percent in 1990, compared with a 10.7 percent growth in the number of federal prisoners.
--The number of prisoners rose 8.9 percent in Western states, compared with increases of 8.3 percent in the Northeast, 7.9 percent in the South and 6.9 percent in the Midwest.
--In the states, the number of sentenced prisoners per capita was highest in South Carolina, Nevada and Louisiana.