We study a 3-region core-periphery model à la Krugman and compare our results with those of the standard 2-region model. The conditions for the stability of the dispersion and concentration configurations are established. Like in the 2-region model, dispersion and concentration can be...

We set the third market model in a dynamic context to decide whether a country can achieve benefits by subsidizing a public rm's exports. We use calculus of variations with the constraint that the welfare is either maximized or grows at constant rate, reflecting the public concern of the firm....