Union Competition and Strikes: the Need for Analysis at the Sector Level

International comparative research has found that strike incidence is higher where two or more unions bargain with an employer ("multi-unionism"), as is common in most European countries, than where only one union does, all else equal. Two pro posed explanations for this relationship, both invoking inter-union rivalry as the main dynamic, are that under multi-unionism, unions (a) make propagandistic use of strikes to attract members, or (b) compete with each other by bidding up bargaining demands. To date, the evidence bearing on these hypotheses has been equivocal because, the author argues, researchers have focused on activity at the national level rather than at the lower levels that are more commonly the nexus for strike formation. The author performs empirical tests using industry-sector-level data for seven European countries for the years 1990-2006, and finds evidence clearly favoring the competitive bargaining hypothesis over the propaganda hypothesis. T n this study, I seek to explain a paradoxical-*-effect of multi-unionism on strike inci dence: although union power within bar gaining structures is lower when two or more unions negotiate with the employer (the defi nition of "multi-unionism") than when only one does, the mainly comparative studies of this subject report higher strike activity under multi-unionism. Unlike in the United States, where multi-unionism disappeared after the A data appendix with additional results, and copies of the computer programs used to generate the results presented in the paper, are available from the author at (Visser 1992). There, it is very common for more than one union to be recognized as a bargaining partner by the employer, both at the level of the individual firm and at the sector level. At the national level, multi unionism can be caused by the division of worker representation between two or more union confederations. Of the 27 European Union member states, 85% have more than one labor union confederation; Hungary, at the extreme, has six. Most labor union confederations are divided along political (50%), religious (25%), or occupational (sta tus) lines (25%), or a combination of these three (Eurofound 2006, 2007). Even in the four countries with just one union confedera tion?the United Kingdom, Austria, Ireland, and Latvia?multi-union bargaining is not unknown: unaffiliated unions and union representation by several unions within the same confederation are found in all four of these nations. Thus, the industrial relations environment in Europe differs sharply from that in North America, where one particular union …