Multiple Marginalization and Trade Liberalization: The Case of the Canadian Dairy Industry

The paper analyzes the welfare impacts of trade liberalization under multiple marginalization through a spatial quilibrium model of provincial dairy markets. Canada’s dairy policy implements a supply management scheme designed to achieve higher domestic prices for farmers, taking into account the mark-up rules used by downstream firms. Our model builds on the reciprocal dumping model of Brander and Krugman (1983) as processing firms from different provinces compete à la Cournot with one another in several provinces. Simulations reveal that welfare in the Canadian dairy sector could increase by as much as $1 billion per year if aggressive tariff cuts were made while moderate liberalization plans would yield annual gains of $234.5 million. Even large producing provinces like Quebec and Ontario gain from trade liberalization. In comparison, a perfect competition model yields more modest welfare gains in the range of $15.6 million and $34.5 million. Finally, we show that the switch in the sign of the transport cost-welfare relation identified by Brander and Krugman (1983) occurs at transport costs that are too high to be policy-relevant