STATE PRISONS IN ILLINOIS ARE OVERCROWDED, WITH AS MANY AS 10,000 CONVICTS HOUSED IN FACILITIES EQUIPPED TO HANDLE NO MORE THAN 7,500 PERSONS ACCORDING TO FEDERAL GOVERNMENT STANDARDS. ONLY ONE NEW PRISON HAS BEEN CONSTRUCTED IN THE PAST 40 YEARS, AND THREE FACILITIES AT LEAST 100 YEARS OLD ARE IN OPERATION. THE LEGISLATURE HAS APPROVED THE CONSTRUCTION OF TWO MEDIUM-SECURITY PRISONS DURING THE 1978-1979 PERIOD, AT A COST OF $58 MILLION. THE PRISON POPULATION IS EXPECTED TO INCREASE SIGNIFICANTLY BY 1980, WITH UP TO 17,000 INMATES BY 1985. PRISON CONDITIONS VARY SUBSTANTIALLY, AND MANY FACILITIES HAVE INADEQUATE VENTILATION, LIGHTING, AND HEAT AND ARE INFESTED WITH INSECTS, RATS, AND MICE. A SENTENCING LAW PASSED IN 1978, KNOWN AS 'CLASS X,' ALLOWS OFFENDERS TO BE INCARCERATED FOR LONGER PERIODS OF TIME FOR CRIMES IN THIS CATEGORY. ARMED ROBBERY IS A CLASS X CRIME FOR WHICH OFFENDERS WILL BE IMPRISONED FOR AN AVERAGE OF 9 YEARS, AN INCREASE OF 5.2 YEARS OVER THE AVERAGE NUMBER OF YEARS THAT WERE SERVED FOR COMMITTING THAT CRIME. IT REMAINS TO BE SEEN WHETHER CLASS X WILL HAVE ANY IMPACT ON THE DETERRENCE OF CRIME IN ILLINOIS. THE TYPICAL INMATE IN THE ILLINOIS PRISON IS A BLACK MALE OF 27 YEARS. EVEN THOUGH BLACKS COMPRISE ONLY 13 PERCENT OF THE STATE'S TOTAL POPULATION, 58 PERCENT OF ALL PRISONERS ARE BLACK. ROBBERY IS THE MOST COMMON CRIME, WITH THE SECOND MOST COMMON OFFENSE BEING BURGLARY. FIGURES INDICATE THAT BLACKS ARE MORE LIKELY TO BE IMPRISONED FOR CRIMES OF VIOLENCE THAN WHITES WHO ARE TYPICALLY SENTENCED FOR PROPERTY CRIMES SUCH AS BURGLARY. ECONOMIC INEQUITIES UNDERLIE THE PROBLEM OF UNEQUAL SENTENCING FOR MINORITIES. PRIMARY ECONOMIC INEQUITIES INCLUDE UNEMPLOYMENT AND LACK OF EDUCATION. SOLUTIONS FOR IMPROVING PRISON LIFE APPEAR TO BE EXPENSIVE.