In discrete choice models the marginal effect of a variable of interest that is interacted with another variable differs from the marginal effect of a variable that is not interacted with any variable. The magnitude of the interaction effect is also not equal to the marginal effect of the...

We examine pollution-reducing R&D by a monopoly firm producing a dirty product. In a dynamic framework with hyperbolic discounting, we establish conditions under which the Porter hypothesis goes through, i.e. environmental regulation increases R&D, thus reducing pollution, as well as increasing...