Most CBSA’s include many “places” (cities, suburbs, etc.), so it would be up to you to decide which place in each CBSA you want to use to represent the central place.Īnother resource you should consider using is NHGIS’s centers of population for tracts. Stata has some utilities for doing that, but I’m not familiar with them, so I don’t know how easy it would be to extract coordinates or measure distances using Stata. You would need a utility that reads shapefiles. NHGIS provides the point files only in shapefile format, so it’s not possible to directly load them into a spreadsheet.(Note also that units of latitude and longitude correspond to widely varying distances on the Earth, so to measure distances accurately, you would either need to compute spherical distance from lat/long values, or you can measure standard Euclidean distances using the projected coordinate system of NHGIS shapefiles–which is generally accurate within the contiguous U.S.) All NHGIS shapefiles use the same system. They instead identify point locations using a “projected coordinate system,” which describes each location as a number of meters removed from a reference meridian and latitude. The Place Point files do not have “lat/long” values per se.You could definitely use NHGIS tract data and place points to measure distances from tracts to CBSA centers. Thank you for any suggestions you might have!įirst, your general plan makes sense. Please correct any fundamental misunderstanding of the purpose of the Place Point files or pitfalls I am missing in this idea. If so, can I import only GISJOIN, Place Point Name and lat/long into a spreadsheet from the Place Point files available for download on the NHGIS Data Finder? Do the NHGIS Place Point files have a lat/long for each “place point”? 2. I think I have found sources for the lat/long of each tract and it seems like the NHGIS Place Point files will be a good measure of the “center” of a place. If I can get the lat/long for each census tract and the lat/long for the “center” of a metro, this doesn’t seem like that bad of a task. I mean “center” in the ecological model sense (Central Business District more than CBSA centroid or center of population). My ultimate goal is to measure the distance in miles between each census tract in a metro area and a single “center” of that metro area. I just realized there was a user forum for IPUMS, great!
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