What I do have on-hand is that NH has a higher median income than any other nation in the world (incl Luxembourg), despite being a net-payer of federal taxes.
It's true that NH has traditionally been in the top-tier of states when it comes to median household income. In the 2016 ACS, it appears to have reached the top:
But its lead is not an overwhelming one. Connecticut's 2016 median hh income was just ~$350 less. According to the the previous ACS in 2015, NH was number 8. And 6 of the top 7 were traditionally blue states.
I seriously doubt it has anything to do with the FSP.
Of course, the median income metric is not the end-all be-all, either. For example, it ignores all the state-provided benefits that those high taxes pay for.
What I do have on-hand is that NH has a higher median income than any other nation in the world (incl Luxembourg), despite being a net-payer of federal taxes.
(Source: https://mises.org/wire/if-sweden-and-germany-became-us-state...)