Bhagwati Jagdish N. author Columbia University. Economics Columbia University. Political Science Panagariya Arvind author Columbia University. International and Public Affairs Columbia University. Economics originator text Articles 1996 English The theory of preferential trade agreements (PTA's), or what might be described in policy terms as the General Agreement on Tariffs and Trade (GATT) Article XXIV sanctioned free-trade areas (FTA's) and Customs Unions (CU's), has undergone two phases of evolution, in two very different modes, largely reflecting the contrasting policy concerns of the time. In this paper, we trace this evolution, offering both a historical context and an intellectual coherence to diverse analytical approaches. Economics 86 2 82 87 1996-05 http://hdl.handle.net/10022/AC:P:14617 NNC NNC 2012-09-06 15:02:52 -0400 2012-09-06 15:08:05 -0400 8640 eng