I’m using the 1960 5% extract. I need to take the PUMAs in that sample and crosswalk them over to 2000-definition PUMAs. IPUMS offers a crosswalk here https://usa.ipums.org/usa/volii/1960g…, but I have noticed that the match is not unique. In other words, for each state & PUMA (1960), there can be multiple state & PUMA (2000) matches. I can understand that a single area might map onto multiple 2000-era PUMAs, but there is no sense of how much (a percent etc) fits into each. Lacking this, I do not understand how to use the crosswalk IPUMS provides.
Has anyone worked with this before? Help!