More recently, two alternative approaches have been proposed that seem to overcome the shortcomings of the previously used methods. Head and Mayer (forthcoming) simulation results indicate that the two preferred methods to tackle the zero-trade problem are the multinomial Poisson based on Eaton, Kortum, and Sotelo (2012) and an EK-Tobit based on Eaton and Kortum (2001). Both methods have the advantage of not requiring exclusion restrictions, as is the case of the Helpman, Melitz and Rubinstein (2008) method, and being easily estimated