Refactored and relocated Base#address_empty? and Base#institution_empty to Address#blank? and Institution#blank?. To address your questions:

1. The intent is to not create records from data extraction that do not contain any meaningful data. Since the default value for any NCS coded attribute that is part of a particular ODE map, but not contained in the current response_set, is 'Missing in Error', I take 'Missing in Error' to be synonymous (for this narrowly-defined purpose) as blank.

2. These fields compose, as you intuited, the "content" of the address, as the other fields left in the ODE map are metadata (rank, type). Please note that institution type is included as content since there is some meaningful data embedded in the type (e.g. 1 = Birthing Center, 2 = Hospital)