“…In addition to the above mixed success of the "joint costs" model, the theory is problematic in explaining the most important "stylized fact" in the strike literature, namely the empirical regularity of cyclical strike incidence (Rees, 1952, O'Brien, 1965, Ashenfelter and Johnson, 1969, Gunderson, Kervin and Reed, 1986, Vroman, 1989, Dickerson, 1994, and Huberman, 2002. As Hirsch and Addison (1986, p. 104) observe "indeed, joint strike costs seem likely to increase with the level of economic activity, leading to the incorrect prediction of counter-cyclical strike activity (incidence).…”