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ANALYSIS OF THE TIME SERIES OF THE IMPRISONMENT RATE IN THE U S STATES

NCJ Number
54136
Author(s)
A BLUMSTEIN; S D MOITRA
Date Published
1977
Length
32 pages
Annotation
TRENDS IN THE PER CAPITA IMPRISONMENT RATE IN 47 STATES ARE EXAMINED, BASED ON AVERAGE DAILY PRISON POPULATION AND THE TOTAL POPULATION FOR EACH STATE FROM 1926 TO 1974.
Abstract
HAWAII AND ALASKA DID NOT POSSESS IMPRISONMENT DATA OVER A SUFFICIENT NUMBER OF YEARS FOR ANALYSIS, AND DATA FROM DELAWARE CONTAINED MAJOR GAPS IN REPORTS AND DISPLAYED EXTREME SHIFTS. THE REMAINING 47 STATES HAD AVAILABLE BASIC DATA ON THE PRISON POPULATION. THE TIME SERIES OF THE U.S. IMPRISONMENT RATE WAS FAIRLY STEADY, STARTING WITH A MINIMUM VALUE OF 76.4 IN 1926, INCREASING IN THE 1930'S, REACHING A MAXIMUM OF 120 IN 1940, DECLINING DURING WORLD WAR II, REACHING A FAIRLY STABLE RATE OF ABOUT 100 AFTER THE WAR, AND DECLINING DURING THE MID-1960'S. THIS TIME SERIES WAS NOT STATISTICALLY SIGNIFICANT AND WAS CONSISTENT WITH THE OBSERVATION OF TRENDLESSNESS FOR TOTAL U.S. PRISON POPULATIONS, INCLUDING THE FEDERAL SYSTEM, EXAMINED IN A PRIOR STUDY. STATES WITH THE HIGHEST MEAN IMPRISONMENT RATES WERE NEVADA, MARYLAND, ALABAMA, GEORGIA, AND FLORIDA. STATES WITH THE LOWEST MEAN IMPRISONMENT RATES WERE NEW HAMPSHIRE, NORTH DAKOTA, RHODE ISLAND, AND MASSACHUSETTS. MATHEMATICAL CONCEPTS OF TIME SERIES ANALYSIS WERE APPLIED TO CATEGORIZE THE 47 STATES INTO GROUPS BASED ON THE PRESENCE OR ABSENCE OF PERIODICITY AND STATIONARITY IN THEIR TIME SERIES. ANALYSIS SUGGESTED STATIONARITY IN 20 OF THE 47 STATES. ALL STATES EXPERIENCED FLUCTUATIONS IN IMPRISONMENT RATES IN VARYING DEGREES. REGIONAL SIMILARITIES WERE MOST APPARENT IN THE MIDWEST AND SOUTH AND ALSO IN THE NORTHEAST. FURTHER STUDY IS RECOMMENDED TO IDENTIFY CAUSES OF OBSERVED VARIATIONS IN THE MEAN IMPRISONMENT RATE ACROSS THE STATES. SUPPORTING DATA ARE TABULATED, AND REFERENCES ARE CITED. (DEP)