Peter T. asks good research questions about the relationship between what people are paying for and what they are getting. Consider that the GDP contribution of Missouri's payday loan industry is the collective interest payments of the borrowers. Consider that in Portland location premiums are for living in nice convenient places, while in Kansas City they are in large part for largely-illusory insulation from regional sociological and public finance problems:
How much of the greater amount of money in Kansas City is just money, as opposed to goods and services? How much is money generated by grifts (payday loans, student debt for courses with no prospect of employment, cancer cures peddled by Republican presidential wannabees...). How hard would it be to map the density of payday lenders in the US? Or to take a chunk of credit card data and work out where the desperate suckers are? How does these and similar indicators correlate to health, income, education? Where do the profits come from, and where do they go? Is anyone doing this?