Geocoordinates of 1980, 1990, and 2000's PUMAS definitions

USA
1

Hello,

I´m working on a project that uses the distance and travel time within different PUMAs across the country as input for some estimations. To calculate the distance and travel time, I need the geocoordinates of each PUMA. Since the definition of PUMAs has changed across time, it is essential to know the latitude and longitude of the population centroid of each PUMA for the 1980, 1990, and 2000’s definitions.

In the geographic tools of IPUMS USA (IPUMS USA | Geographic Tools), I found files with information for these years, but none of these files contain the geocoordinates corresponding to each PUMA. I also checked the TIGER/Line Shapefiles of the Census Bureau (TIGER/Line Shapefiles), but the oldest available information is for 1992, and it does not contain anything related to PUMAs.

Therefore, can anyone tell me if this information exists and if that is the case, where to look for it, or where I can request it, please?

Thank you!

2

To my knowledge, neither IPUMS nor any other data provider has computed population centroids (i.e., mean centers of population) for PUMAs. IPUMS also doesn’t directly provide standard spatial centroids for older PUMAs. (I’m guessing you’re already aware that more recent TIGER/Line shapefiles generally do include centroid latitudes and longitudes, so more recent IPUMS USA or NHGIS shapefiles, which are based on TIGER/Line, also typically include the centroids.)

Most GIS software (Esri ArcGIS, QGIS, etc.) includes tools to generate standard centroids from polygons and to export point latitudes and longitudes. You could use those tools to derive centroids from IPUMS PUMA shapefiles. If you specifically need mean population centers, the work is definitely more involved. For some guidelines, the Census describes its methodology here.

For our part, we’ll include the idea of providing PUMA population centers in our work planning, but we probably won’t be able to do that soon.

3

Hi Jonathan! Thank you for your response. I´ll try the GIS approach you are suggesting, but it would be great if eventually IPUMS could provide this information.