Jerry A. Hausman is the John and Jennie S. MacDonald Professor of Economics at MIT in Cambridge, Massachusetts, USA. He has taught at MIT for 30 years. He is Director of the MIT Telecommunications Economics Research Program. Professor Hausman received the John Bates Clark Award from the American Economics Association in 1985 for the most outstanding contributions to economics by an economist under 40 years of age. He also received the Frisch Medal from the Econometric Society. Professor Hausman academic research has been in a number of areas. He has published numerous papers in econometrics and applied microeconomics. His recent applied research has been in differentiated products and in telecommunications. Professor Hausman has previously done research in the effects of taxation on the economy, the economics of aging, and in energy and environmental economics. His recent applied papers are on topics including the effect of new goods on economic welfare and their measurement in the CPI, new telecommunications technologies including cellular 3G and broadband, regulation of telecommunications and railroads, and competition in network markets. His recent econometrics papers include estimation of difference in difference models, semi-parametric duration models, weak instruments, and errors in variable in non-standard situations.