Inaccuracies in low income housing geocodes:when and why they matter

Scholars across disciplines frequently employ data on housing developments subsidized by the National Low Income Housing Tax Credit (LIHTC). We find that the geographic coordinates for these developments, generated by the U.S. Department of Housing and Urban Development (HUD), are frequently inaccurate. Using both the population of data from California and a national sample, we find that HUD-provided geocodes are inaccurate nearly half the time while Google-generated geocodes are almost always more accurate. However, while Google’s geolocation is more likely to be accurate, when it is inaccurate, it deviates from the true location by a much greater distance than HUD. We therefore recommend that scholars use Google-generated geocodes for most research applications where the localized environment matters; however, in studies where observations are aggregated to a larger area, researchers may prefer to use HUD geocodes, which are more frequently inaccurate but typically by smaller distances.