Subhash C. Ray is a Professor of Economics at the University of Connecticut, USA. His principal area of research is nonparametric measurement of productivity and efficiency using Data Envelopment Analysis (DEA). His reference textbook Data Envelopment Analysis: Theory and Techniques for Economics and Operations Research (Cambridge University Press) was published in 2004. He is an Associate Editor of Journal of Productivity Analysis. He has served as guest editor of special issues of Journal of Productivity Analysis and  Indian Economic Review. He was a member of the Editorial Board of Indian Economic Review. He has lectured and conducted workshops on DEA in different countries including China, India, Korea, England, Brazil, Peru, Germany, Malaysia, and Turkey, among others. He received the W.W. Cooper Lifetime Contribution Award from International DEA Society in 2016. Robert G. Chambers wasborn in Washington, DC and raised in nearby Rockville, Maryland. He received his undergraduate training at Georgetown University, his MS degree from the University of Maryland, and his PhD from the University of California (Berkeley). He joined the faculty at the University of Maryland in 1979 and has been there ever since apart from leave to serve as Senior Economist at the US President’s Council of Economic Advisers. He is a Fellow of the Agricultural and Applied Economics Association. His areas of interest include production economics, microeconomic theory, decision-making under uncertainty, and agricultural economics. He is married and has three sons, Christopher, Geoffrey, and Timothy. He currently resides in Maryland, New York, and New Mexico with his wife, Michelle, his youngest son, Tim, and their Portuguese Water Dogs, Nelson and Skipper. Subal Kumbhakar Professor Subal C. Kumbhakar (http://bingweb.binghamton.edu/~kkar/) is a University Distinguished Research Professor in Economics at the State University of New York at Binghamton. His main area of research is applied microeconomics with a focus on estimation of efficiency in production using cross-sectional and panel data. Professor Kumbhakar is a Fellow of Journal of Econometrics (1998) and a distinguished author of Journal of Applied Econometrics (2017). He holds an Honorary Doctorate degree (Doctor Honoris Causa) from Gothenburg University, Sweden (1997).               Professor Kumbhakar is currently a co-editor of Empirical Economics and served as an associate editor of Empirical Economics since 2001, American Journal of Agricultural Economics (1997-1999). He is serving as a Board of Editors of Journal of Productivity Analysis since 1998, Technological Forecasting and Social Change: An International Journal since 1991, and International Journal of Business and Economics since 2002, Macroeconomics and Finance in Emerging Market Economies since 2007, Applied Econometrics, http://appliedeconometrics.cemi.rssi.ru/AppEc_en.html since 2016, Ecos de Economía: A Latin American Journal of Applied Economics, http://publicaciones.eafit.edu.co/index.php/ecos-economia/index since 2016. He is a Board Member of Journal of Regulatory Economics since 2015. Professor Kumbhakar is the co-author (with Knox Lovell) of Stochastic Frontier Analysis (2000), A Practitioner's Guide to Stochastic Frontier Analysis Using Stata (with Hung-Jen Wang and A. Horncastle) (2015) both published by the Cambridge University Press.  Google Scholar Citations: https://scholar.google.com/citations?user=-rB5HVsAAAAJ&hl=en Wikepedia: https://en.wikipedia.org/wiki/Subal_Kumbhakar Personal webpage: https://sites.google.com/binghamton.edu/subalckumbhakar/home