Abstract: In economic applications it is often the case that the variate of interest is non-negative and its distribution has a mass-point at zero. Many regression strategies have been proposed to deal with data of this type but, although there has been a long debate in the literature on the appropriateness of different models, formal statistical tests to choose between the competing specifications are not often used in practice. We use the non-nested hypothesis testing framework of Davidson and MacKinnon (1981), “Several tests for model specification in the presence of alternative hypotheses”, Econometrica, 49, 781-793, to develop a novel and simple regression-based specification test that can be used to discriminate between these models.