My main field of interest is international trade theory, though I have also written on industrial organisation and consumer theory, fields which continue to feature in my current research. My major current interest is the implications of large firms in global markets: more formally, I am exploring the theory of oligopoly in general equilibrium and its implications for a variety of topics in international trade, including trade patterns, foreign direct investment (both greenfield and cross-border mergers), multi-product firms, and heterogeneous firms. Another interest is the measurement of globalisation, trying to establish theoretically sound and practically useful methods for comparing real income and national outputs across countries. Finally, I continue to work with Jim Anderson on aspects of trade policy, pursuing themes we explored in our recent book Measuring the Restrictiveness of International Trade Policy (MIT Press, 2005). Our current project is to devise practical rules of thumb for trade policy reform in economies where tariffs are an important source of government revenue.