Diversification and win rate in NLRB certification elections

This research examined industrial diversification patterns and win rates within the 1977–1979, 1983–1985 and 1992–1994 periods for all NLRB certification elections of the 30 most active unions in 1977–1979. We found significant change in diversification and little change in average win rates over the study period. The general trend was less total diversification and more unrelated diversification in 1992–1994 relative to 1983–1985 and 1977–1979. Total diversification and election frequency had no impact on win rates. However, related diversification had a significant positive influence on union win rates for elections recorded outside unions’ core organizing industries.