THE STUDY CASES (358 FINES AND 643 PRISON SENTENCESMINUS IRRELEVANT CASES) WERE CATEGORIZED AS FOLLOWS: PERSON WHO DID NOT REPEAT AN OFFENSE OVER A 5-YEAR FOLLOWUP PERIOD; PERSONS WHO DID REPEAT AN OFFENSE; PERSONS WHOSE SENTENCES WERE SUSPENDED; AND PERSONS WHO ACTUALLY SERVED A SENTENCE. DETERMINATIONS WERE ALSO MADE OF LENGTH OF TIME SERVED AND AGE AT TIME OF CONVICTION. MAJOR FINDINGS INCLUDE THE FLLOWING: (1) FIRST OFFENDERS WHO, ONCE CONVICTED, DO NOT REPEAT AN OFFENSE ARE FOUND IN COMPARABLE NUMBERS AMONG ADULTS AND JUVENILES; AND (2) THE TENDENCY TO REPEAT OFFENSES IS VERY SLIGHT FOR BOTH SUSPENDED AND ENFORCED SENTENCES OF UP TO 3 MONTHS, VERY STRONG FOR SUSPENDED SENTENCES BUT SLIGHT FOR ENFORCED SENTENCES FOR SENTENCES OF 3 TO 6 MONTHS, STRONG FOR BOTH SUSPENDED AND ENFORCED SENTENCES OF 6 TO 12 MONTHS, AND VERY SLIGHT FOR SUSPENDED OR ENFORCED SENTENCES OF 12 TO 18 MONTHS. ONE CONCLUSION DRAWN FROM THE ANALYSIS OF SENTENCE DURATION AND RECIDIVISM IS THAT, FOR SENTENCES OF MORE THAN 9 MONTHS, SUSPENDED AND ENFORCED SENTENCES ARE EQUALLY EFFECTIVE DETERRENTS. OTHER ANALYSES SHOW THAT HABITUAL OFFENDERS TEND TO BEGIN THEIR CAREERS WITHIN A 7-YEAR PRIOD BEGINNING AT 14.5 YEARS OF AGE, THAT THE TENDENCY TOWARD RECIDIVISM AMONG HABITUAL OFFENDERS DECREASES BY 2 PERCENT PER YEAR OF AGE, AND THAT, IN 1965, AS MANY RECIDIVISTS RETIRED FROM CRIME IN PARIS AS ENTERED INTO IT. THE FINDINGS ALSO SUGGEST THAT ANY CRIME 'EXPLOSION' IN FRANCE IS DUE NOT TO THERE BEING MORE RECIDIVISTS, BUT TO THE FACT THAT RECIDIVISTS ARE COMMITTING MORE OFFENSES. SUPPORTING DATA ARE INCLUDED. (1KM)