or just where the data's bad. One of the highest ratios of median rent to median income (what they're trying to call their gentrification ratio) in the map of SF is shown in SOMA near 4th and Folsom. I used to live on that block, the median income is most certainly not $16k. It's just not. Half of that block group is non-residential, either Yerba Buena or office buildings, so maybe that's doing something weird to the data, but overall I think this attempt at a "gentrification" measure doesn't at all work.

I'd also expect walkable areas where people spend less money on cars to have higher rents compared to median incomes.