####Many of the data sources from the above website seem to have been moved as of 6/13/17.
###https://www.census.gov/programs-surveys/economic-census.html
###Note: Census tract data not available at these urls as of 6/13/17
###Census tracts seem to be smaller than zip codes particularly in urban areas, so this might be a more precise unit of data
###Problems: it may be difficult (or impossible) to determine census tract for VC, Fortune 500, and Medical Centers. ACS data by census tract is not publicly accessible.