I see that constraints to produce valid imputations can be implemented in the Gauss version of Amelia. However, Gauss is not available to me at this time, and it may take me quite some time to figure out how implement the constraints, since I've never used Gauss. In view of the circumstances I want to make a request, hoping that I'm not stepping out of the boundaries of the list. I wonder if somebody in the list would be willing to generate the imputed data sets for a reasonable fee. I would provide the data, imputation model, and the needed restrictions. Thanks, Leonelo E. Bautista, MD, DrPH Assistant Professor University of Wisconsin Medical School Population Health Sciences 610 Walnut Street, 703 WARF Madison, WI 53726-2397 Phone: (608)265-6176 Fax: (608)263-2820 -----Original Message----- From: Gary King [mailto:king@harvard.edu] Sent: Monday, June 07, 2004 3:01 PM To: Leonelo Bautista Cc: amelia(a)latte.harvard.edu Subject: Re: [amelia] impossible values Usually if you transform the data before Amelia, impute, and then transform back, you can avoid this problem. See http://gking.harvard.edu/amelia/node22.html for more details about this and other procedures in more complicated situations. Best of luck, Gary King : Gary King, King(a)Harvard.Edu http://GKing.Harvard.Edu : : Center for Basic Research Direct (617) 495-2027 : : in the Social Sciences Assistant (617) 495-9271 : : 34 Kirkland Street, Rm. 2 HU-MIT DC (617) 495-4734 : : Harvard U, Cambridge, MA 02138 eFax (617) 812-8581 : On Mon, 7 Jun 2004, Leonelo Bautista wrote: are how with