In this paper we propose a categorical time-varying coefficient translog cost function to estimate technical change and productivity. The primary feature of this model is that each of its coefficients is expressed as a nonparametric function of a categorical time variable, thereby allowing each...

Using the standard Ricardian model, we developed the numerical result of Samuelson (2004) with general conditions. Specifically, our analysis shows that, the cumulative technological progress of the South will undermine the welfare of the North even before the relative productivities of the two...