A model of union interest was advanced with self-evaluation as linking economic and socio-economic realities to willingness to join a union in the context of a new psychological framework. Using a representative survey sample of non-union US employees (N=1,010), the model was tested with structural equation modelling techniques. Support was generally found for the hypothesized model, although a revised model was considered. In particular, psychological self-sufficiency fully mediated the influence of financial dependency on self-enhancement (overconfidence in one's abilities and efficacy), and, in turn, self-enhancement fully mediated the influence of psychological self-sufficiency on union interest. Suggestions stemming from the model for future theory, research, and application are provided.