Are trade and immigration policies substitutes or complements? Using the two-sector model in the Dutch disease literature, the paper argues that the degree of a resource boom changes labor-intensive firms’ preferences over immigration policy and how they respond to trade liberalization. As trade liberalizes, firms in the tradable sector move into the resource industry or into the non-tradable sector during a resource boom, leading to a decline in support for pro-immigration policy. Without such exit options in resource-poor economies, firms seek to remain viable by supporting pro-immigration policy under trade liberalization. Trade and immigration policies are substitutes during a resource boom but are complements otherwise. Rigorous empirical analyses with new data on immigration policy show that changing firm preferences translate directly into policy outcomes. The variation in immigration policy across multiple labor-scarce economies cannot be fully understood without accounting for trade liberalization and resource booms. The paper poses a serious challenge against the conventional wisdom that trade and immigration policies have always been substitutes. An important implication of the paper is that open economies under growing resource booms will restrict immigration even further. ∗Prepared for the International Political Economy Society (IPES) conference at Georgetown University, Washington, D.C., November, 14–15, 2014. This material is based upon work supported by the National Science Foundation Graduate Student Research Fellowship under Grant No. DGE 0718128. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author and do not necessarily reflect the views of the National Science Foundation. †Ph.D. Candidate, Department of Political Science, University of Michigan, Ann Arbor, 5700 Haven Hall, 505 South State Street, Ann Arbor, MI 48109-1045; E-mail: adrianjs@umich.edu.