GEO1_PK identifies the household's province within Pakistan in all sample years. Provinces are the first level administrative units of the country. GEO1_PK is spatially harmonized to account for political boundary changes across census years. Some detail is lost in harmonization; see the comparability discussion. A GIS map (in shapefile format), corresponding to GEO1_PK can be downloaded from the GIS Boundary files page in the IPUMS International web site.
The full set of geography variables for Pakistan can be found in the IPUMS International Geography variables list. For cross-national geographic analysis on the first and second major administrative level refer to GEOLEV1, and GEOLEV2. More information on IPUMS-International geography can be found here.