Research on the effects of collective bargaining by library clerical workers indicates that effects are often less dramatic than expected, and that there does not appear to be a single "union effect." Although one study found hefty gains for library workers with collective bargaining agreements, other studies have found no significant gains by the same classes on employees in similar libraries. The bulk of the evidence indicates that there are probably some wage advantages that can be attributed to collective bargaining; however, the gains are not nearly as large as those achieved by workers in other occupations. For example, library workers are estimated to gain 4 to 8% wage improvements through unions as compared to 12-15% increases for workers in industrial occupations. While it is undoubtedly true that unions can slow activities and significantly obstruct progress, several studies have shown that collective bargaining contributes to improved operational efficiency. Increased productivity is thought to result from management's being pressured by a union to be more accountable in a union environment. It is also argued that collective bargaining can improve productivity by opening up communication channels. However, the net effect of collective bargaining on productivity and organizational efficiency is still in doubt. (SD)