This chapter provides evidence on the impact of ICT at the macroeconomic and sectoral level. It shows that ICT investment has contributed to growth and labour productivity in all OECD countries for which data are available, but more in the United States than in any other OECD country. Moreover, rapid technological progress in the ICTproducing industry has contributed to rapid productivity growth in some OECD countries, notably the United States, Finland, Ireland, Korea and Sweden. In a few countries, notably the United States and Australia, there is also evidence that sectors that have invested much in ICT, for example wholesale and retail trade, have experienced more rapid productivity growth. These impacts of ICT on productivity have not disappeared with the recent slowdown; part of the acceleration in aggregate productivity growth in certain OECD countries, notably the United States, is structural and could continue in the years to come...