Based on this [page] (https://international.ipums.org/international/geography_variables.shtml) and this paper, the IPUMS constructs GEO2_BR: 1) by harmonizing municipalities across time; 2) by “regionalizing” them to meet the 20,000 inhabitants threshold for confidentiality reasons.
The above page and paper also say that the IPUMS uses as much as possible the documentation provided by the partner statistical agencies (the IBGE in Brazil) to perform 1) and 2).
Since the IBGE has has its own harmonized municipalities, called AMC (“áreas mínimas comparáveis”), I am wondering whether the IPUMS’s GEO2_BR and the IBGE’s AMC only differ due to 2). In other words, if all Brazilian were above the 20,000 inhabitants threshold, would there be any difference between IPUMS’s GEO2_BR and IPUMS’s AMC?

Thanks a lot.

The procedures IPUMS uses to harmonize municipal boundaries differ from those used by AMC. While IPUMS uses a combination of changing boundaries and confidentiality thresholds, to the best of my knowledge, AMC only uses changing boundaries. Additionally, with IPUMS data, lower-level boundaries are nested within parent boundaries (i.e. municipal boundaries that are nested within states boundaries cannot cross state lines). Finally, AMC uses boundaries from 1872-2010 and our boundaries are harmonized from 1980-2010. Therefore, the harmonization approach used by IPUMS to create GEO2_BR differs from that used by IBGE to create AMC.