TY - JOUR AU - Evans,George W. AU - Honkapohja,Seppo AU - Williams,Noah TI - Generalized Stochastic Gradient Learning JF - National Bureau of Economic Research Technical Working Paper Series VL - No. 317 PY - 2005 Y2 - October 2005 UR - http://www.nber.org/papers/t0317 L1 - http://www.nber.org/papers/t0317.pdf N1 - Author contact info: George Evans Department of Economics 1285 University of Oregon Eugene, OR 97403-1285 Tel: 541/346-4662 Fax: 541/346-1243 E-Mail: gevans@uoregon.edu Seppo Honkapohja Bank of Finland Finland E-Mail: Seppo.Honkapohja@bof.fi Noah M. Williams Department of Economics 1180 Observatory Drive University of Wisconsin Madison, WI 53706-1393 Tel: 608/263-3864 E-Mail: nmwilliams@wisc.edu AB - We study the properties of generalized stochastic gradient (GSG) learning in forward-looking models. We examine how the conditions for stability of standard stochastic gradient (SG) learning both differ from and are related to E-stability, which governs stability under least squares learning. SG algorithms are sensitive to units of measurement and we show that there is a transformation of variables for which E-stability governs SG stability. GSG algorithms with constant gain have a deeper justification in terms of parameter drift, robustness and risk sensitivity. ER -