), 'Gradualism in Free Trade Agreements: A Theoretical Justification', Journal of International Economics 59: 367-97 -- Clemens … Trade in Services', pp. 11-46 in Services Trade in the Asia-Pacific Region, edited by Takatoshi Ito and Anne O. Krueger …. Redding and Peter K. Schott (2012), 'The Empirics of Firm Heterogeneity and International Trade', Annual Review of Economics 4 …