Hi @InvTech Just following up on this, would you happen to know why the VISITOR_HOME_CBGS contains ""? A possible reason I’ve come across is from @evan-barry-dewey’s post here which I’ve quoted below. I’m trying to understand if dropping these observations will introduce some sort of bias in our analysis. Thanks!
Number of CBGs and Census Tracts in Trade Areas.
Advan cuts the number of CBGs in a trade area to the top 1,000 and number of tracts in a trade area to the top 400. SafeGraph did not. This is a temporary measure to limit the size of the data and make it easier to ingest. Advan generates home/work trade areas as 4 fields - geohash 6 (i.e., g6), g5, g4, and g3, so the more distant areas have lower granularity. Advan reserves the right to modify the schema in the future to similarly reduce the overall data size without losing granularity at the local level.
Effect: the visitor columns (visitor_home_cbgs, visitor_home_aggregation, etc.) will contain a much smaller number of CBGs / Census Tracts. Additionally, CBGs / Tracts that are distant from the POI (and less likely to have significant visitation to the POI) will be missing.