“The day California passed the tax increase, I received three calls from concerned athletes,” accountant Steve Piascik, president of Piascik & Associates, told me. His firm is one of the largest representatives of professional athletes in the country.

Mr. Piascik isn’t urging his clients to pack their bags just yet, but he says that some are considering moving to reduce their tax liabilities. And several of his clients, whose names he won’t disclose, have already ordered their lives around the tax code: They play for teams in California but live elsewhere for tax reasons.

Former Los Angeles Angels of Anaheim right fielder Torii Hunter (who recently signed with the Detroit Tigers) lived in Prosper, Texas, during the baseball off-season. The main reason he “moved to Texas is because it doesn’t have state income tax,” the outfielder told the Orange County Register last year.

The benefit of living in a state without an income tax can be diminished by the “jock tax” that states impose on money earned by athletes when they’re playing or training in the state. (Luckily for baseball players, spring training is in no-tax Florida or low-tax Arizona.) But in sports like tennis and golf where athletes can train anywhere in the world, a preponderance happen to migrate to states without an income tax.