“…CGE trade models under imperfect competition have been used since the work of Cox and Harris on the US-Canada free trade area (1985), and that of Smith and Venables (1986), on closer integration in Europe. Such models have been widely used to assess the impact of North Amerian economic integration (De Melo and Tarr, 1992;Francois and Shiells, 1994); intra-European integration (Gasiorek et al, 1991(Gasiorek et al, , 1992Allen et al, 1998;Haaland, 1993), as well as regional integration beween and within other country groupings (Brown et al, 1997(Brown et al, , 2000. 2 In contrast, residual imputation or analytically more sophisticated econometric models typically focus on identifying the change in trade patterns arising from integration.…”