1. Productivity differences;Quarterly Journal of Economics,2001
2. Berman, E. and Machin, S. (2004), “Globalization, skill-biased technological change and labour demand”, in Lee, E. and Vivarelli, M. (Eds), Understanding Globalization, Employment and Poverty Reduction, Palgrave Macmillan, New York, pp. 39-66.
3. Economic integration, process and product technology adoption, and relative skill demand;Review of International Economics,2008
4. Technical progress, urban unemployment, outputs, and welfare under variable returns to scale;International Review of Economics and Finance,2002