Gordon Sondland's being registered to vote in Seattle reminds me of Chris Dudley, the 2010 GOP candidate for governor who once claimed residence in Washington to avoid Oregon income tax. How do the tax people determine where you officially live?—Amateur Economist

The Portland-Vancouver-Hillboro Metropolitan Statistical Area is the only major population center to straddle the border between a state with no sales tax (Oregon) and a state with no income tax (Washington). As such, it provides people who are temperamentally inclined to avoid taxation with a unique opportunity for arbitrage: live in Washington, avoiding income tax, and buy everything in Oregon, avoiding sales tax.

Gordon Sondland, the U.S. ambassador to the E.U. and Seattle resident who recently testified in the Trump-Ukraine investigation, has never registered to vote in Oregon, so he can't be accused of leaving for tax reasons. Former Portland Trailblazer Chris Dudley, however, was frank in admitting that, during his playing days, he moved from Oregon to Washington on the advice of his accountant.

This raised some eyebrows during his campaign, especially since he kept his Portland residence during his entire tenure with the team and, according to neighbors, continued to spend a lot of time there.

Income earned in Oregon—like Dudley's NBA salary—is subject to Oregon income tax no matter where you live. But if you're the kind of person who can afford to play musical residences to beat the tax man, chances are you have investment income, endorsement cash, or other rich guy-type revenue streams that come from out of state—and that Washington won't tax.

There is no hard-and-fast rule governing who is or isn't an Oregon resident. According to the state Department of Revenue, you're a resident if: "You think of Oregon as your permanent home. Oregon is the center of your financial, social, and family life. Oregon is the place you intend to come back to when you are away."

Take me home, country roads! It turns out that whether you owe Oregon income tax mostly depends on subjective feelings in your heart that—let's be honest—would be pretty easy to lie about. In the end, there's just one thing that can settle your residency status once and for all: an Oregon income tax audit.