The government puts out cost of living indexes for select urban areas, so we could just go by that: http://www.census.gov/compendia/statab/cats/prices/consumer_

The government puts out cost of living indexes for select urban areas, so we could just go by that: http://www.census.gov/compendia/statab/cats/prices/consumer_price_indexes_cost_of_living_index.html http://www.census.gov/compendia/statab/cats/prices/consumer_... The data is from 2010, so a bit outdated, but it puts Manhattan at 2.1x the national average and SF at 1.64x the national average. The high cost of housing also pushes more people to renting instead of buying, eliminating any tax deductions for mortgage interest that people in low-cost areas are more likely to take.