An enhancement of modern free trade area theory

This paper constructs a framework for analysing the welfare effects of free trade areas. We provide an alternative verification of the Panagariya-Krishna proposition on free trade areas, shortening the proof, covering a broader set of circumstances, and showing the necessary income flows to guarantee welfare gains to all members. The paper provides a theoretical parallel to the important Kemp and Wan custom union theory. Copyright 2007 , Oxford University Press.