Pierre Bachas is an Assistant Professor at ESSEC and an Economist in the Macroeconomics and Growth Team in the Development Research Group at the World Bank. His research focuses on public finance in developing countries. In particular, on optimal tax design and challenges to tax collection faced by low- and middle-income countries as a result of tax evasion, informality and differences in economic structure. Prior to joining the bank he was a postdoctoral researcher at Princeton University. He holds a Bachelor and Masters in economics from the LSE and a PhD in Economics from UC Berkeley.