TO MEASURE THE RELATIONSHIP BETWEEN TREATMENT AND CRIME, THE EXPERIMENTERS MEASURED THE MONTHLY NUMBER OF PROPERTY OFFENSES REPORTED TO THE DETROIT POLICE, AND RELATED THIS TIME SERIES TO MONTHLY ENROLLMENTS IN ALL DETROIT DRUG TREATMENT CENTERS, THE PRICE OF HEROIN, AND OTHER VARIABLES THAT AFFECT THE LEVEL OF CRIME. THE MAJOR FINDINGS ARE THAT A 1.0 PER CENT INCREASE IN TREATMENT ENROLLMENT IS ASSOCIATED WITH A 0.23 PER CENT DECREASE IN PROPERTY CRIME, AND THAT A 1.0 PER CENT RISE IN HEROIN PRICE IS ACCOMPANIED BY A 0.16 PER CENT RISE IN CRIME. THE AUTHORS ALSO CARRIED OUT THREE SUPPORTING ANALYSES ON RELATED TOPICS. THE FIRST EXAMINES HOW MUCH MUTUAL RELATIONSHIPS BETWEEN VARIABLES BIASED THE MEASUREMENTS OF THE CRIME-TREATMENT-PRICE RELATIONSHIPS USING THE ABOVE PROCEDURE. OF PARTICULAR IMPORTANCE IS THE POSSIBILITY THAT TREATMENT AND HEROIN PRICE ARE RELATED TO CRIME THROUGH A 'REVERSE' MECHANISM: THAT HIGHER CRIME LEVELS PUSH UP ADDICT INCOMES WITH THE JOINT OUTCOME OF REDUCING THE NEED FOR TREATMENT TO AVOID HIGH COSTS OF DRUGS, AND BIDDING UP THE PRICE OF HEROIN. THE AUTHORS FIND THAT THIS MECHANISM HAS SOME PREDICTIVE POWER, AND THAT THE ABOVE ESTIMATES OF THE EFFECT OF TREATMENT AND PRICE ON CRIME ARE NOT SERIOUSLY BIASED. THE SECOND SUPPORTING ANALYSIS DEALS WITH THE QUESTION OF HOW TO INDUCE ADDICTS TO ENTER TREATMENT, ASSUMING THE DESIRABILITY OF DOING SO. FOR THIS ANALYSIS, THE AUTHORS EXAMINE THE DETERMINANTS OF THE NUMBER OF NEW ENROLLMENTS DURING THE MONTH (INFLOW). IT WAS FOUND THAT THE RATE OF TREATMENT INFLOW WILL INCREASE WITH HIGHER HEROIN PRICES AND NUMBERS OF NARCOTICS ARRESTS, BOTH OF WHICH MEASURE THE COST OF DRUG INVOLVEMENT. FINALLY, URINALYSIS DATA IS EXAMINED TO OBTAIN A DIRECT MEASURE OF HEROIN USE BY TREATMENT CLIENTS. THE AUTHORS FIND THAT ONLY 11 PER CENT OF URINE SAMPLES OF METHADONE PATIENTS ARE 'HEROIN DIRTY'. ASSUMING THAT TESTING WAS RANDOM AMONG INDIVIDUALS, THIS MEANS THAT ONLY 11 PER CENT OF METHADONE CLIENTS STILL USE HEROIN, COMPARED TO THE ALMOST 100 PER CENT WHO USED IT BEFORE ENTERING TREATMENT. (AUTHOR ABSTRACT)....DMC