ONE OF THE CENTRAL CRITERIA FOR EVALUATING THE EFFECTIVENESS OF THE COLLECTIVE BARGAINING PROCESS IS THE EXTENT TO WHICH UNIONS AND EMPLOYERS ARE ABLE TO RESOLVE THEIR DIFFERENCES WITHOUT DEPENDENCE ON THIRD PARTIES. THE CONCERN FOR PROMOTING FREE COLLECTIVE BARGAINING IS ESPECIALLY IMPORTANT IN PUBLIC SECTOR JURISDICTIONS THAT HAVE ESTABLISHED IMPASSE PROCEDURES AS ALTERNATIVES TO THE RIGHT TO STRIKE. THOSE INVOLVED IN THE STRUCTURING OF SUCH IMPASSE PROCEDURES ARE CONCERNED THAT THEIR VERY EXISTENCE WILL CREATE A DEPENDENCY ON THESE PROCEDURES AS A REPLACEMENT FOR FINAL DECISIONMAKING IN COLLECTIVE BARGAINING. WHETHER OR NOT THIS FEAR IS CONFIRMED IN FACT IS TESTED BY APPLYING AN EXPERIMENTAL MODEL THAT ANALYZES THE NEGOTIATING EXPERIENCES OF POLICE AND FIREFIGHTER UNITS IN THE STATE OF NEW YORK BEFORE AND AFTER THE INSTITUTION OF AN IMPASSE PROCEDURE THAT INCLUDES ARBITRATION. THE SAMPLE FOR THIS STUDY CONSISTS OF ALL MUNICIPALITIES IN NEW YORK THAT BARGAIN WITH UNITS OF BOTH FIREFIGHTERS AND POLICE (EXCLUDING NEW YORK CITY, WHICH IS COVERED BY ITS OWN IMPASSE PROCEDURES). DATA WERE COLLECTED BETWEEN 1974 AND 1976 IN SEMISTRUCTURED PERSONAL INTERVIEWS WITH THE UNION AND MANAGEMENT NEGOTIATORS IN THESE UNITS. IN 1968, A LAW GOVERNING IMPASSE PROCEDURES WAS ESTABLISHED TO PROVIDE FOR FACTFINDING WITH RECOMMENDATIONS, FOLLOWED BY A LEGISLATIVE HEARING. IN 1974, THE LAW WAS CHANGED TO PROVIDE FOR CONVENTIONAL COMPULSORY ARBITRATION FOLLOWING FACTFINDING. A STUDY OF THE BARGAINING HISTORY OF THE SAMPLE UNITS BETWEEN 1968 AND 1976 SHOWS THAT AN INCREASING PROPORTION OF THE UNITS WENT TO IMPASSE OVER THE ENTIRE PERIOD STUDIED; THERE WAS A HIGH RATE OF REPEATED USE OF IMPASSE PROCEDURES BY THE SAME CITIES AND BARGAINING UNITS; AND THE ADOPTION OF COMPULSORY ARBITRATION IN 1974 LED TO A MARGINAL INCREASE IN THE PROBABILITY OF IMPASSES IN SMALL AND MEDIUM-SIZED CITIES. THE ADOPTION OF ARBITRATION, HOWEVER, WAS A LESS IMPORTANT DETERMINANT OF IMPASSES THAN SEVERAL OTHER FACTORS IDENTIFIED IN THE MODEL. THE APPENDIXES REPORT THE STUDY DATA. (RCB)