In standard models of New Economic Geography the overall regional price index in the centre is lower than in the periphery, because trade in manufacturing imposes transportation costs whereas trade in agriculture is assumed to be costless. Since real world observations suggest higher overall...

The paper shows that in a spatial price equilibrium under monopolisitc competition welfare can be increased by subsidising transport. Therefore transport can be said to exert a positive (pecuniary) externality. This is demonstrated by introducing a subsidy into a partial spatial price...