Source: Arindrajit Dube, Ethan Kaplan, and Owen Thompson, ILR Review, Vol. 69 no. 4, August 2016
From the abstract:
The authors estimate the impact of nurse unions on health care quality using patient-discharge data and the universe of hospital unionization in California between 1996 and 2005. They find that hospitals with a successful union election outperform hospitals with a failed election in 12 of 13 potentially nurse-sensitive patient outcomes. Hospitals were more likely to have a unionization attempt if they were of declining quality, as measured by patient outcomes. When such differential trends are accounted for, unionized hospitals also outperform hospitals without any union election in the same 12 of 13 outcome measures. Consistent with a causal impact, the largest changes occur precisely in the year of unionization. The biggest improvements are found in the incidence of metabolic derangement, pulmonary failure, and central nervous system disorders such as depression and delusion, in which the estimated changes are between 15% and 60% of the mean incidence for those measures.