Containing eight of Gene Grossman's and Elhanan Helpman's previously published articles, this work acts as a compaion to the monograph "Special Interest Politics". The first three chapters focus on campaign contributions and candidate endorsements - two of the tools that interest groups use in their efforts to influence policy outcomes. The remaining chapters present applications to trade policy issues. Grossman and Helpman demonstrate how the approaches developed in their monograph can shed light on tariff negotiations, and on the viability of bilateral free trade agreements. They also examine the forms that regional and multilateral trade agreements are likely to take and the ways in which firms invest abroad to circumvent trade barriers induced by political pressures.