But a few thing I'm missing are: - second (higher) order availability: even if the hospital you need to go to is within biking distance, is the hospital itself sourcing it's materials (needles, plasters etc.) locally? Otherwise you might end up at a hospital that can't treat you - in your modelling you only accounted for weather effects and elsewhere assumed that, hopefully, immigration will somehow be managed well. Suppose it will not - how will you manage that and ensure you will not loose everything, when everyone suddenly moves to where you are and all wealth is taken from people who have some? Is Traverse city perhaps sufficiently insulated so that people won't easily reach it? Does it have a strong police?

Lastly, I'm recommending the "nodes of persisting complexity" article, if you're interested. They carry out an analysis like you do, but at country level. Sadly, the US doesn't score too high.