A Microeconometric Analysis of Spillovers within the Canadian Wage Determination Process

T HE objective of this paper is to develop and test models of wage spillovers utilizing a large micro data base constructed from Canadian collective bargaining wage contracts signed between 1966 and October 1975 (the introduction of wage controls in Canada). There are two basic approaches to the wage spillover hypothesis that can be found in the literature. 1 Institutional spillover models, characterized by Dunlop's wage contours and Ross' orbits of coercive comparisons, emphasize the distributional structure of wage rates between occupational-industrial groups. A second approach follows the tradition of microeconomic labour market theory and emphasizes relative wages, labour mobility, labour turnover costs, etc. For example, a simple Marshallian model would include both the firm's own wage rate as well as competing wage rates as determinants of labour supply (and consequently wage changes). More recently Phelps (1968) has proposed a generalized excess demand model of frictional labour markets in which a profit-maximizing firm establishes an optimal wage differential between its own wage rate and competing wage rates.2 Unfortunately it may be impossible to identify empirically the precise "theoretical" origin of wage spillover effects. The existence of wage spillovers is totally consistent with economic models of wage determination as well as being consistent with institutional hypotheses that emphasize key bargains, wage leadership, pattern wage adjustments, maintenance of "historical wage differentials," etc.3 Thus, our interpretation of the theoretical rationale for wage spillovers must, of necessity, be somewhat agnostic. Turning to the empirical evidence, three studies have advanced evidence pertaining to wage spillovers, each study based on a very different statistical methodology. Perhaps the classic study in this area is the Eckstein-Wilson (1962) paper which emphasizes a number of institutional aspects of the wage determination process. Eckstein and Wilson provide empirical evidence, based on the identification of specific wage rounds, supporting a combined market-institutional spillover model of wage determination within the U.S. manufacturing sector. For a "key group" of industries, identified largely from impressionistic evidence, wage changes are determined by profit and unemployment rates based on the aggregate rates for all industries within the key group. Outside the key group of industries, wages are principally determined by wage spillovers from the key group. Unfortunately, the underlying wage round technique employed by Eckstein and Wilson is notoriously difficult to implement, i.e., to identify unambiguous aggregate wage rounds. McGuire and Rapping (1967) have challenged the Eckstein-Wilson study on the grounds that at best their evidence lends weak support to their institutional hypothesis, that their central result for the key group of industries is ambiguous, and finally that they have not resolved the problem of distinguishing between neo-classical labour supply forces and institutional spillover effects. McGuire and Rapping's own model (1968), which is tested with cross-sectional data (industries at the state level), reveals that while market forces play an important role in the relative wage determination process for the U.S. manufacturing sector, wage spillovers from steel and automobile key bargains (particularly steel) are also relevant explanatory variables. Received for publication July 13, 1978. Revision accepted for publication May 23, 1979. * University of Guelph. We gratefully acknowledge the helpful comments that we have received from Doug Auld, David Dodge, Mark Mueller, and John Vanderkamp. This paper could not have been written without the financial support of the Anti-Inflation Board and the diligence of an exceptionally fine research assistant, Jane Forster. None of the above-named individuals, nor the Anti-Inflation Board, should be held responsible for the arguments and conclusions of this paper. 1 For a thorough review and critique of spillover theories, see Burton and Addison (1977). 2 This optimal wage differential takes into account the turnover costs associated with recruiting, hiring, and training new workers. 3 For further discussion of this "identification problem," see Addison and Burton (1979). [ 213 ]