What is the best immigration policy for the United States?

Libertarian Land goes to the logical extreme: free immigration, with exceptions only for immigrants who would obviously generate large externalities (like, say, known terrorists). This recognizes that even modest restrictions are often costly and ineffective. Communicable diseases, for example, can readily enter a country via travel by legal residents, despite restrictions on immigration.

The United States is unlikely to mimic Libertarian Land in the near future, and the risk of short-term disruptions from vastly greater immigration might suggest gradual rather than drastic changes in policy.

Still, the message is clear: the United States needs more, not less, immigration.

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