search for: paprameters

...) censored dependent variable. e and u are the normally distributed error terms. z'a is the participation equation and x'b is the expenditure equation. If we would remove the participation equation from the model we would end up with a type I tobit-model. In the tobit-model the same set of paprameters and variables determine both the discrete probability of non-zero outcome and the level of positive expenditure. In the double-hurdle-model we have separate parametrization of the participation and consumption decisions. I can estimate tobit-model using function survreg(). But what about this doub...