Hi, I have two question on how to create dummy variables. Suppose... 1. I have a time series of annual data, say from 1970 to 2000. How do I create a dummy for the period 1975-1980 (1 for this period, 0 otherwise)? 2. I have cross-sectional data by states. How do I create a dummy for the southern region where I know the states in that region? Thanks, Walt -- ________________________ Walter R. Paczkowski, Ph.D. Data Analytics Corp. 44 Hamilton Lane Plainsboro, NJ 08536 ________________________ (V) 609-936-8999 (F) 609-936-3733 walt(a)dataanalyticscorp.com www.dataanalyticscorp.com