Following up on earlier posts, I think that the public choice argument would take account of the difference between the power of the head of state and the power of the legislative branch of the government. Heads of state have the power to negotiate multilateral trade agreements, although they typically cannot pass the legislation needed to sign the agreement. Legislators typically have no power to negotiate such agreements. To see the difference, one must first understand the positions of the special interests under alternative free trade proposals. Consider first unilateral free trade. If a president or legislator advocates unilateral free trade, he will find himself disliked by firms that face competition from imports because these firms are relatively certain they will lose and their losses are significant. He will be liked by potential exporters or other beneficiaries who understand the economics of international trade. (Under the usual assumptions, dinars spent on foreign goods must eventually be spent by the foreigners on domestic goods or something that benefits citizens.) But these people don't study international trade theory and, even if they did, the gains to any particular exporter or other beneficiaries are uncertain, particularly in a competitive market. People in their role as consumers, of course, stand to gain from free trade. But the benefits to each are relatively small. Moreover, there is rational ignorance about the effects of government policies, leaving most consumer-voters in the dark about the effects of trade policies. So the special interest anti-free trade group is relatively strong in the pressure group competition that influences presidents and legislators. That strength is reduced in a bilateral trade agreement, as the gains to some exporters become more certain. Also a bilateral agreement can often be tailored so that it does not hurt particularly important special interest domestic producers and so that particularly important exporters are pinpointed as beneficiaries. Multilateral agreements /significantly/ reduce the relative strength of firms facing import competition by significantly strengthening the interests of exporters. Thus GATT, the ECM, and WTO could be more successful from a political standpoint than unilateral decisions and bilateral trade agreements. As I recall, this argument, or something like it, is made in the typical international trade texts (see Krugman and Obstfeld for example) and also in Mankiw's introductory textbook. One complaint I have about the Lusztigs book, as reported by O'Brien, is partly that it fails to recognize this pressure and how it plays out, given the powers of the head of state and the legislature. Under most constitutions, only heads of state can negotiate international trade deals. They are subject to the same pressure as legislators, it seems to me, albeit more concentrated on specific legislators as Sam pointed out. The most important difference is not the differential concentration of pressure, however, but the powers. If I understand it correctly, the theory presented by Lusztigs seems to be a kind of after-the-fact justificationist theory. It says that because presidents have negotiated free trade deals, they must be subject to less anti free-trade pressure, on balance. The problem is that legislators are not even in a position to negotiate such deals. So how can we know the different relative pressure that they, as a group, would face if they were in that position? Pat Gunning