Census years linked to subdistrict and district data

New in SHRUG2 are aggregate datasets at the census subdistrict and district levels. Central to these datasets is the concept of a base year: the single Population Census year (2011, 2001, or 1991) through which we link each dataset into the SHRUG. As a result, subdistrict and district data are published in the base year of the dataset. For example, the 2013 Economic Census was linked to the 2011 Population Census, whereas the 1990 Economic Census was linked to the 1991 PC.

Importantly, this means that users cannot automatically merge subdistrict/district datasets with different base years. In the example above, the 2013 EC district data will be uniquely identified by pc11_state_id pc11_district_id, whereas the 1990 EC data will be identified by pc91_state_id and pc91_district_id. Shrid data can always be automatically merged across years, while constituency data can be merged as long as you do not attempt to merge pre-delimitation data (identified by ac07_id) with post-delimitation data (ac08_id). If users want to generate custom datasts with custom base years (e.g. 2013 EC data in 1991 census districts), they can use our public tool IdConverter.