Despite Arthur Lewis’s predictions and arguments in the 1950s, it is clear that the informal sector is here to stay. Over the last half a century, the dynamics of rich and poor economies have further impressed the fact that ‘informality’ is not a passing phenomenon. In this context, this volume from UNU-WIDER is a great contribution to an appreciation of the opportunities and challenges in the informal sector. The countries selected show the rich experience in the informal sector of big and small economies from different regions of the world. A better understanding of the informality will enable policy makers and development practitioners to bring out the best from this sector, contributing to a world with more economic growth and less poverty. This book accomplishes this task very well. —Sudharshan Canagarajah, Senior Economist, the World Bank