Turning no tides: Union effects on partisan preferences and the working-class metamorphosis

Relying on panel data for Germany, Switzerland, the United Kingdom, and the United States, the paper examines the impact of union membership on partisan preferences. By leveraging panel data to control for time-invariant selection effects, we show that unions exert a small consistent left-wing influence on the average wage earner who becomes affiliated, but they are no longer able to modify the preferences of working-class members. A longitudinal approach reveals that changes in partisan preferences can be linked to members' preexisting predispositions and to the prevalent political views within unions. Unions mainly attract individuals who already share their political inclinations before joining. These preexisting left-wing convictions allow an additional left-wing shift to take place through a value congruence mechanism provoked by interactions with long-term union members who are even more left-wing oriented than the newcomers. Symmetrically, working-class joiners exhibit less pronounced left-wing inclinations before becoming affiliated, a gap that widens further after they join as a consequence of their unmet expectations.