Local vs global: ideas to improve GCC

Per discussion on HN, see https://news.ycombinator.com/item?id=13611926, I'm thinking:

• redo linear regression with current larger dataset
• parse by region or function or both to see if it yields different results
• consider doing it separately on BLS data, (although that would be very US specific)

Per https://news.ycombinator.com/item?id=13616005:

"You'd think their system would treat all locations in the same Core Based Statistical Area as the same. Better yet, treat all locations in the same Combined Statistical Area as the same; in fact, the definition of a CSA is a set of adjacent CBSAs with interconnected commuting patterns. [...] Data at: http://www.census.gov/population/metro/data/def.html"