When you are paid by the government to do government work out of your home, that’s income. It’s like “telecommuting.”
If the per diem is part of the compensation of your employment when you are in fact, home, it’s income.
The Government of Alaska could make it a condition of the job for the Governor to reside in Juneau during the term of office. AFAIK, there is no such requirement.
The distances are immense ~ far greater than those of other states, and that's just halfway (Alaska is roughly the size of three Texas' and one Indiana).
The Governor is NOT required to live in Juneau, but "overnighters" are undoubtedly out of the question, plus, there are duties she must attend to in Juneau.
Just figuring out what her perdiem really is constitutes one accounting nightmare. Figuring out what part is taxable is yet another nightmare. The third is that if she's claiming perdiem in Wasilla and then flies off to tend to state business in Fairbanks (for example), she's still on perdiem, but if she returns to Wasilla that's going to be counted one way, and if she returns to Juneau that's going to be computed differently.
You are right—there is no requirement that the governor live in the mansion in Juneau. By the way, the governor is SAVING the state a lot of money by living in her own home and claiming per diem. $18,000 over a 2 year period-—since she is not living at the mansion, the governor’s personal chef, who earned $50,000 per year, was let go. The very old house costs a fortune to heat, but the thermostat can be turned way down when the governor is not there, etc. Other household help at the mansion is also not needed, so in the long run, she’s saving Alaskans money.