Alfred Greiner is professor of Economics at Bielefeld University. His research interests are in dynamic macroeconomics with special emphasis on topics in economic growth and fiscal policy. He has published numerous articles and was invited to author the survey article "Models of Economic Growth" for the UNESCO Encyclopedia of Life Support Systems.
Willi Semmler is Chair and Professor of Economics at New School University, co-director of the Center for Empirical Macroeconomics, Bielefeld University and Research Fellow at the Bernard Schwartz Center for Economic Policy Analysis. He is the author of numerous articles and several books including Stochastic Dynamic Macroeconomics (OUP, 2006).