CRIMINALS CAN MOVE FREELY ACROSS POLICE JURISDICTIONS. CONSOLIDATION IS ONE MECHANISM FOR DEALING WITH THIS. HOWEVER, CONSOLIDATION REDUCES LOCAL CONTROL OF POLICE AND MAY NOT PERMIT ECONOMIES-OF-SCALE TO BE REALIZED. COOPERATION BETWEEN AGENCIES, ON THE OTHER HAND, ENABLES EACH AGENCY TO RETAIN ITS IDENTITY AND LOCAL CONTROL WHILE COOPERATING WITH ONE ANOTHER IN AREAS OF MUTUAL AGREEMENT. DURING THE PERIOD FROM JUNE 1974 TO MAY 1975, A SURVEY WAS CONDUCTED OF 1,200 POLICE PATROL AGENCIES IN 80 SMALL TO MEDIUM-SIZED STANDARD METROPOLITAN STATISTICAL AREAS. INPERSON INTERVIEWS, AS WELL AS PHONE CONTACTS AND MAIL QUESTIONNAIRES WERE USED TO DOCUMENT THE RANGE OF SERVICES PROVIDED BY URBAN POLICE FORCES, THE VARIATIONS IN THEIR INTRAORGANIZATIONAL STRUCTURE, THE DIVERSITY OF INTERORGANIZATIONAL ARRANGEMENTS AMONG POLICE AGENCIES AND BETWEEN AGENCIES AND SUPPORT FACILITIES, AND THE INTERRELATIONSHIPS AMONG THESE VARIABLES. THE EFFECTS OF THE DEMOGRAPHIC CHARACTERISTICS OF THE POPULATIONS SERVED AND STATE LEGAL CONSTRAINTS ON THE STRUCTURE OF THE METROPOLITAN POLICE INDUSTRY ALSO WERE EXAMINED. FRAGMENTATION (THE EXISTENCE OF MANY POLICE JURISDICTIONS) AND AGENCY MULTIPLICITY WERE FOUND TO BE POSITIVELY RELATED TO MUTUAL ASSISTANCE AND MEMBERSHIP IN MUTUAL AID AGREEMENTS. AS THE SIZE OF THE DOMINANT PRODUCER OF POLICE SERVICES IN THE METROPOLITAN AREAS INCREASES, HOWEVER, THE INCIDENCE OF INFORMAL COOPERATION DROPS. THE EXISTENCE OF GREATER AMOUNTS OF MUTUAL AID AMONG POLICE AGENCIES IN FRAGMENTED METROPOLITAN REGIONS MIGHT HELP TO EXPLAIN WHY POLICE SERVICES IN THOSE AREAS ARE RATED MORE HIGHLY. GIVEN SOME INCENTIVE TO IMPROVE SERVICE QUALITY (ELECTORAL ACCOUNTABILITY, PROFESSIONAL NORMS, THREAT OF CONSOLIDATION, ETC.), COOPERATION IS APPARENTLY AN EFFECTIVE MEANS FOR OVERCOMING ANY PROBLEMS OF LAW ENFORCEMENT CAUSED BY METROPOLITAN JURISDICTIONAL FRAGMENTATION. REFERENCES ARE PROVIDED. (RCB)