U.S. trade preference programs promote economic development in poorer nations by providing export opportunities. The Generalized System of Preferences, Caribbean Basin Initiative, Andean Trade Preference Act, and African Growth and Opportunity Act unilaterally reduce U.S. tariffs for many products from over 130 countries. However, three of these programs expire partially or in full this year, and Congress is exploring options as it considers renewal. The author was asked to review the programs' effects on the United States and on foreign beneficiaries' exports and development, identify policy trade-offs concerning these programs, and evaluate the overall U.S. approach to preference programs. To address these objectives, the authors analysed trade data, reviewed trade literature and program documents, interviewed U.S. officials, and did fieldwork in six countries. This is an excerpted and indexed version.