Winners and Losers in Customs Unions: An Experimental Investigation

In the context of a Competitive Ricardian Model (CRM), one can ask whether it is possible to relate winners and losers from a CU based on comparative advantage considerations. This was pursued by Venables (2003), who showed that careful consideration of a country’s comparative advantage – with the rest of the world relative to that with its partners in the CU- yields predictions about winners and losers. Starting from initial tariff equilibrium, in a 3 country model with a continuum of goods, he shows that a country with ‘extreme’ comparative advantage will be more vulnerable to trade diversion. In this experiment, the 3 x 3 Competitive Ricardian Model (CRM) in two scenarios multiple import tariffs and a customs union. We fully characterise the equilibrium under both. Starting from a tariff distorted situation, we find that when a customs union is formed there is an increase in trade flows among members; a rise in individual consumption of some goods; a clear terms of trade effect and the existence of trade diversion. Our experimental results support the simulation findings of Venables (2003), who showed that countries which have ‘extreme’ comparative advantage in a customs union will generally be more vulnerable to trade diversion.