How to get the "density" of conspuma?


I notice there is a population “density” of PUMAs, however, I want to use the ConsPUMAs which are consistent across 2010-2020 geographic identity. Is there any variable or method to obtain the population density of the Conspuma?

Thank you for the reply!

There is no variable that provides the population density of 0010 ConsPUMAs; you will have to calculate this yourself. The process will depend on whether you want to calculate the density of the whole PUMA or the population-weighted average density as reported in DENSITY.

For the first case, you will need to obtain the total population and land area for each ConsPUMA. The 2010 population of each ConsPUMA is provided on the 0010 ConsPUMA definition page in the CPUMA0010 Summary document. The area of each ConsPUMA can be calculated using either the provided boundary file or by summing the land area (the Part_Land column) across each unique value of CPUMA10 in the 2000-2010 PUMA Crosswalk file on the linked definition page.

For a population-weighted average, you will need to obtain a crosswalk of Census tracts to 0010 ConsPUMAs and apply the method described on the DENSITY variable description page. You can obtain a crosswalk between tracts and 2010 PUMAs (with tract-level population and land area) by using the Data Finder tool on IPUMS NHGIS. You will want to add a table that reports total population and select both tract and PUMA level (note that tract level data is only available for 5-year ranges). You can then use the summary document to aggregate 2010 PUMAs to 0010ConsPUMAs.

I wanted to follow up and share some more information that I learned.

First, there is an easier way to obtain unweighted ConsPUMA densities. The population density of 0010 ConsPUMAs is available as a variable (POPDENSGEO2) on IPUMS International since the second level geographic identifier for the ACS samples on IPUMS-I (GEOLEV2) are ConsPUMAs. These are the unweighted population density values for the entire ConsPUMA. To obtain this data, you will need to create an extract that includes one of the United States samples, GEOLEV2, and POPDENSGEO2. You can then use a stats package to collapse your data to a single observation of each ConsPUMA. Please note that applications to access IPUMS International data are reviewed by our staff and approval to access data typically takes about one week.

Second, the process I outline in the previous response for obtaining a crosswalk between tracts and 2010 PUMAs using IPUMS NHGIS doesn’t work the way that I thought it did. Instead, you can obtain a crosswalk from census tracts to 2010 PUMAs from this Census Bureau webpage. You can then obtain the census tract densities from IPUMS NHGS. Tract-level population data is available for both 5-year ACS ranges and for decennial census years (e.g. 2010 and 2020).

thanks for the detailed clarification!