A study on the effects of a more unionized workforce in the United States, on the representation of women and minorities in the management of enterprises.
It finds that while stronger unionization is associated both with more women and more minorities represented in the overall workforce and in management, this effect is only marginally significant.
it may be a selection effect of more unionized enterprises.
It uses union elections as its base of analysis, and thus can not exclude self-selection effects of people joining more heavily unionized enterprises rather than unionization increasing representation in its conclusions.