GEO1_ ML1998 identifies the household's region within Mali in 1998. Regions are the first level administrative units of the country. A GIS map (in shapefile format), corresponding to GEO1_ ML1998 can be downloaded from the GIS Boundary files page in the IPUMS International web site.
The full set of geography variables for Mali can be found in the IPUMS International Geography variables list. For cross-national geographic analysis on the first and second major administrative level of any country refer to GEOLEV1, and GEOLEV2. More information on IPUMS-International geography can be found here.