Empirical wage spillovers are often observed, but their theoretical ex
planation is controversial because they are consistent with institutio
nal wage comparisons stemming from fairness or union politics, but als
o with neoclassical alternative wages or correlated labor demand shock
s. The nature of wage spillovers is analyzed using a data set of Unite
d Automobile, Aerospace, and Agricultural Implement Workers of America
(UAW) wage settlements, The results support the hypothesis that insti
tutional wage spillovers augment neoclassical economic forces in deter
mining wages, albeit with some weakening after 1980.