There is little doubt that two of the hot button issues of our time involve, first, international trade of goods and services and, second, the movement of people from one country to another, sometimes for short periods but sometimes with the intention of acquiring either rights of citizenship or permanent occupation in their new destination country. The central choice in both areas is whether nations, in particular the United States, should adopt parallel regimes of free trade and free immigration. It has long been clear that the case for free immigration is harder to make out than the case for free trade. That difference cannot be chalked up solely to nativism or improper racial sentiment. Those forces are surely at work in some cases, but not in all. What can be shown, however, is that a comprehensive and unified approach to these two areas, and to the relationship between them, justifies that initial assessment, even if it does not justify many of the restrictions commonly found in dealing with immigration and naturalization. It is best to start with a brief description of the pros and cons of free trade before tackling the thornier issue of free immigration of individuals across borders.