To cope with steep losses in membership and eroding legal protections, some unions have begun to look outward for help. Scholars likewise point to broad-based coalitions as a potential route to labor’s revitalization. Yet surprisingly little is known about union coalition work, from when and why it occurs to what union allies typically bring to the table. We take up these issues with a unique dataset on strike events from the 1990s and 2000s, contributing to labor and social movement research. First, we show that despite considerable academic interest in union outreach to other social movements, this phenomenon remains fairly rare. Second, our findings demonstrate how the immediate threat to unions posed by employer intransigence matters not just for the mobilization of external allies, as the social movement literature would expect, but also for the assistance brought to bear by those allies, which has received relatively little attention from scholars. Third, although we find important distinctions in unions’ propensity for outreach, results suggest a more nuanced picture of union activity than previously conceived. In various ways during strike events, both social movement unions (typically highlighted in the literature) and declining industrial unions are turning to coalition partners.

The income share of the super-rich in the United States has grown rapidly since the early 1980s after a period of postwar stability. What factors drove this change? In this study, we investigate the institutional, policy, and economic shifts that may explain rising income concentration. We use single-equation error correction models to estimate the long- and short-run effects of politics, policy, and economic factors on pretax top income shares between 1949 and 2008. We find that the rise of the super-rich is the result of rightward-shifts in Congress, the decline of labor unions, lower tax rates on high incomes, increased trade openness, and asset bubbles in stock and real estate markets.