Thanks a lot for the quick response. I did what you suggested and it worked great. I do have one more question if you do not mind. Since I know have 5 output, which one am I supposed to use. Or is there a way to compile them? I am working with STATA and tries to I tried to use Ken Schieve's program, but somehow could not manage to make it work. I still need to do more manipulations with the data (take first differences, etc) before I start running regressions.

Borislava Mircheva
PhD Candidate
Department of Economics
American University
https://eagle1.american.edu/~bm6265a/

-----Gary King <king@harvard.edu> wrote: -----

To: Bobbie Mircheva <bmircheva@american.edu>
From: Gary King <king@harvard.edu>
Date: 09/07/2007 06:20PM
cc: amelia@lists.gking.harvard.edu
Subject: Re: [amelia] negative values

one way is to transform the data to an unbounded scale. e.g., if all
observed and unobserved values of a variable are positive, then transform
the positive ones by taking the log. then impute with Amelia (on the
unbounded log scale). then transform the resulting imputed and observed
values by taking the exponential.

you can also use the priors in Amelia II to help as well.

Gary

---
Gary King
David Florence Professor of Government,
Director, Institute for Quantitative Social Science
Harvard University, 1737 Cambridge St, Cambridge, MA 02138
http://GKing.Harvard.Edu, King@Harvard.Edu
Direct 617-495-2027, Assistant 495-9271, eFax 812-8581

On Fri, 7 Sep 2007, Bobbie Mircheva wrote:

> Hi,
> I have a big panel dataset on countries in Sun-Saharan African with
> information on trade and infrastructure between 1990 and 2005.
> Unfortunately some of the infrastructure data is missing and I was using
> Amelia to fill in the gaps. However, the program returned a bunch of
> negative values. How can I fix this?
> Thanks a lot
> Bobbie
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