So, when I ran across this database of all prisons and correctional facilities in the nation on Enigma.io, I used the dataset to put together this visualization displaying all 137 private prisons and correctional facilities – all of which are owned entirely by just five different private enterprises – and then added a simple chloropleth layer displaying incarceration rates by state underneath.
Can’t see what’s going on too well at the resolution below? Here’s a standalone package:
This visualization is a case in which deeper statistical analysis and consideration of multiple variables would’ve bolstered the possible argument that private prisons lead to higher incarceration rates, if such a claim is true, that is (i.e., determining a statistically significant correlation between number of inmates in each state with the number of private prisons or correctional facilities located there).
Such a data-driven study of the private prison industry conducted by U.C. Berkely Ph.D. student Chris Petrella concluded that blacks are disproportionately incarcerated in private prisons as opposed to public jails.
A similar methodology could be applied to private prison populations in general, as many private prisons are required by state or local law to have a minimum quota of around 90 to 95 percent occupancy to keep their government contracts. It would be interesting, too, to visualize that data in a manner more easily accesible to the average user than an academic research journal.
Tools I would’ve used before new CartoDB:
- Batch geocode by findlatitudelongitude to geocode the address data into lat/long coordinates.
- ColorBrewer2.org to find equidistant color scales.
- Locating .shp, .kml or .geojson polygons for the U.S. states.
- Excel to merge tables and bind geographic with numeric data.
- Who knows?