In celebration of the fiftieth anniversary of the Stolper-Samuelson Theorem, this volume collects in one place the original Stolper-Samuelson articles as well as the most significant later contributions that interpret, extend, and test the basic result. It also includes reflective papers by both Wolfgang F. Stolper and Paul A. Samuelson, an overview of the literature, and an annotated bibliography. Contributors to the volume, either in reprints of their original articles or in new commentary, are Robert E. Baldwin, Sundari R. Baru, Jagdish N. Bhagwati, John S. Chipman, Alan V. Deardorff, Wilfred Ethier, Ronald W. Jones, Murray C. Kemp, Ulrich Kohli, Paul R. Krugman, Edward E. Leamer, Stephen P. Magee, Lloyd A. Metzler, Ronald Rogowski, Paul A. Samuelson, Jose A. Scheinkman, Robert M. Stern, Wolfgang F. Stolper, and Leon Wegge.