Chrome. Seems to work on Firefox, though. Weird.

Okay, here's my two cents:

1) I agree w/ bfv. Even though lower-income individuals generally spend more than 30% on rent, they ought to be spending less than 100% on rent, which means that the map should populate with numbers that are some percentage of income. Say, 50%? Which means you wouldn't have to account for food spending, as that and any other potential necessary and as-yet unaccounted for cost (e.g. transportation, basic health, child support) would be reflected in the remaining percentage of income. That would also cut down on a lot of unnecessary coding/widgets, maybe?

2) It's extremely interesting for academic purposes, but for practical purposes it would have to be a lot more localized. If somebody can't afford much more than minimal housing cost, it's gotta be pretty frustrating to look at a map and see that you could afford to live at your current income level... across the country.

Unfortunately, this would make your job a lot more difficult. You mentioned that you'll eventually work on a zoom function, which is difficult enough. But besides that, if you're dealing with cost on a local level rather than national averages, wouldn't you then have to take into account relative income? For instance, housing might be really cheap in Shohomish County, WA compared to your income in Washington County, OR, but that decrease in housing price might come with a corresponding and compensatory decrease in income.

In which case it might be better to map by some sort of relative income index rather than static housing prices- something that shows how much bang you could get for your buck here rather than there.

Which isn't to rip into what you did, because it's incredibly neat.

Out of curiosity, what do you do for a living?