THE FUNDAMENTAL HYPOTHESIS OF THE ECONOMIC APPROACH TO CRIME IS THAT OFFENDERS AND THOSE WHO ATTEMPT TO CONTROL CRIME RESPOND ON THE WHOLE TO MEASURABLE OPPORTUNITIES OR INCENTIVES. IT IS THE VERIFICATION AND ESTIMATION OF THE EXTENT OF OFFENDER'S RESPONSIVENESS TO AND THE COST OF PRODUCING AND METING OUT SUCH INCENTIVES THAT ARE POSED AS CENTRAL TARGETS OF SCIENTIFIC INVESTIGATION. IT APPEARS FROM THIS LIMITED SURVEY THAT BOTH ECONOMIC REASONING AND AN EXTENSIVE BODY OF RECENTLY DEVELOPED EVIDENCE BASED ON THIS REASONING ARE COMPATIBLE WITH HYPOTHESIS THAT POTENTIAL OFFENDERS RESPOND TO INCENTIVES, BOTH POSITIVE AND NEGATIVE; THAT LAW ENFORCEMENT AUTHORITIES REACT TO THE THREAT OF CRIME ON THE BASIS OF THIS HYPOTHESIS; AND THAT EQUILIBRIUM ANALYSIS IS A POTENTIALLY POWERFUL TOOL FOR ANALYZING AND PREDICTING TRENDS IN THE FREQUENCY OF VARIOUS ILLEGITIMATE ACTIVITIES AT DIFFERENT TIMES AND PLACES. THE SUPPORTED PROPOSITION THAT THE PROBABILITY AND SEVERITY OF CRIMINAL SANCTIONS EXERT PURE DETERRENT EFFECTS, INDEPENDENT OF ANY INCAPACITATIVE EFFECTS OF SPECIFIC SANCTIONS, SHOULD NOT BE CONFUSED, HOWEVER, WITH ANY RECOMMENDATION FOR EITHER GREATER OR LESSER EMPHASIS ON THEIR USE AS INSTRUMENTS OF CRIME CONTROL. THE DESIRABILITY OF SPECIFIC LAW ENFORCEMENT ACTIVITIES AND SANCTIONS MUST BE DETERMINED NOT ONLY BE THEIR DETERRENT EFFECTIVENESS, BUT BY THEIR RELATIVE SOCIAL AND ECONOMIC COSTS. THE BASIC CONCLUSIONS PRESENTED ABOUT THE MAGNITUDES OF OFFENDERS' RESPONSIVENESS TO VARIOUS INCENTIVES CANNOT BE REGARDED AS FINAL. THEY ARE BASED ON THE BROADEST, MOST COMPREHENSIVE BODY OF EVIDENCE CURRENTLY AVAILABLE, BUT THIS BODY OF EVIDENCE IS STILL INADEQUATE. NOTES AND REFERENCES ARE PROVIDED. (RCB)