Public Sector Unionization and Government Contracting: A Meta-analysis of Four Decades of Empirical Evidence

Within the large body of literature on government contracting, the effect of public sector unionization on contracting out is still unsettled even after decades of research. Previous literature proposes that unionization may both inhibit and motivate contracting out, making the net effect difficult to predict. Through a meta-analysis of 232 effects drawn from 49 existing studies spanning over four decades, we find that jurisdictions with higher levels of public sector unionization generally contract out more in public service delivery. Further metaregression analysis suggests that unionization has a weaker effect when governments engage in intergovernmental contracting but a stronger effect when governments contract out for technical services. Unionization also has a stronger effect on how much a government contracts out than on whether a government contracts out. Overall, unionization is a relevant, but not necessarily robust, factor in driving contracting out, and its exact effect may vary slightly by context.