We know far too little about how and why unions deal with one another, though we increasingly realize the life-and-death importance to organized labor of this under-studied matter. All the more welcome, therefor, is a rare intensive study of inter-union relations in a particularly revealing industry, as the book under review sheds valuable light on the question of whether labor solidarity is presently "meaningful or a hollow pretense." (p.4).

David J. Walsh begins by substituting for casual conception-alizations of the labor movement a more rigorous view of it as a differentiated and structured (both formally and informally) inter-union network. He further breaks with convention by choosing the union realities of a chaotic industry to study (of 190 new carriers since 1978, 116 were out of business by 1994).

PWalsh persuasively contends, however, that "we learn more about the possibilities and limits of labor solidarity by examining an industry in which a tradition of inter-union cooperation has not yet been established, than by looking elsewhere for shinning success stories." (p.5).

Far more successfully, and certainly in greater conceptual detail than any preceding writer, Walsh explains the complex origins of inter-union relations, why such relations wax and wane, and how they affect labor relations outcomes. He pioneers in the application of academic tools conspicuous by their absence from the industrial relations literature.

Specifically, he draws on organizational theory, though he takes care to qualify its essentially utilitarian thrust. He also uses network analysis to get at the social embeddedness of individuals and organizations, the better to conceptualize airline labor as a whole and examine the place of individual unions within that larger system.

Drawing on his 1989 phone survey of 33 union spokespersons most likely to handle boundary -spanning activities with other airline industry unions, Walsh offers a quantitative analysis of all 1,024 possible pairs of relations. A multiple regression-QAP analysis enables him to draw even more from the data. as does his later use in network analysis of CONCOR blockmodeling and a multi-dimensional scaling plot of CONCOR correlations.

As impressive as is its methodological sophistication the book is not without puzzling gaps in attention. Specifically, while the Coalition of Flight Attendant Unions is characterized as "arguably the best example of coalition-building that airline labor has to offer," no attention is paid to the part gender may play in explaining its success.

Similarly, nothing is said about the major role of social class in explaining the coolness of the machinists and the pilots toward each other (or how both have seemingly overcome this in the case of the largest employee buyout in history, the United Airlines deal)..

Still more regrettable is the total neglect of the 1981 PATCO strike of air traffic controllers, arguably the most significant labor-management conflict of the post-war period, and one that dramatically impacted on labor relations in and outside of the airline industry (the machinists initially helped the strikers, while the pilots helped the employers throughout).

These omissions notwithstanding, the book is a major academic contribution, one that already redefines the entire subject for students of organizational relations in general and unions in particular. Likely to be a benchmark for years to come, it offers more in fewer pages than many volumes twice its size. While its conclusions are without surprise, and everything said is qualified to a fare-thee-well, the book warrants attention from students of trade unionism here and abroad.

Although union leaders and staffers were never the intended audience for this scholarly work, they can learn much of value from it, especially about hindrances to labor solidarity (once, that is, that someone, hopefully Walsh himself, translates this version from jargon into English).

Offered in part to help labor better understand that inter-union relations are far more than a mere "tactic to be trotted out when unions are in trouble," the book may yet prove of critical aid in helping labor renew itself. (p.168).

On Different Planes: An Organizational Analysis of Cooperation and Conflict among Airline Unions. By David J. Walsh. Ithaca, NY: ILR Press, 1994. Pp. xiv+170. Cloth, $36; Paper, $18. Index; Bibliography.