This article expands and modifies the concept of Margaret Keck and Kathryn Sikkink of a transnational advocacy network (TAN) to explain the interaction between institutional and noninstitutionalized actors in the complex policy-making cycles in the European Union. I look at how the gender equality TAN successfully raised the issue of sexual harassment in the EU in the early 1980s and brought it into the amended 1976 Equal Treatment Directive in 2002 and explain this with three factors. First, TANS create policy expertise through the exchange of information and knowledge across borders among activists, experts, and policy makers, with both insiders and outsiders sharing an interest in creating transnational expertise. Second, newer international organizations and institutions, like the EU offer activists a more open terrain to advance their goals. Third, the "boomerang pattern" identified by Keck and Sikkink occurs as a "ping-pong effect" in the EU because of its multilevel policy-making structure, which provides both challenges and opportunities for advocates.
