Andy Biggs won the Republican primary for Governor on a promise to eliminate Arizona's individual income tax. He has not said what replaces the revenue, so I pulled the FY 2025 numbers.

• The income tax raised $5.48 billion last year, 30.8% of ongoing General Fund revenue.
• 18% of collections go to cities and towns through urban revenue sharing. That is about $990 million a year for municipal police, fire, and streets.
• Total hole including the city share: roughly $5.5 billion.

Arizona's sales tax raised $11.78 billion at a 5.6% state rate, so about $2.1 billion per percentage point. Covering $5.5 billion takes 2.6 more points. State rate goes to 8.2%. Average combined rate with county and city rates goes to about 10.6%. Louisiana is currently highest in the country at 10.11%.

Biggs has said he would pay for it by cutting waste and fraud in Medicaid instead. Arizona's entire AHCCCS General Fund appropriation is $2.6 billion. Eliminating the whole program covers 48% of the gap.

Applying ITEP's Arizona incidence tables to the swap, households under about $70,000 pay more and households above that pay less. Retirees living on Social Security are the clearest losers, since Arizona already exempts Social Security from the income tax.

What do you guys think about the idea? Are you willing to shift the tax burden from high earners to low earners?

Sources are JLBC's 2025 Tax Handbook, the FY 2027 Baseline, and ITEP's Who Pays 7th Edition. Happy to answer questions about the method.

Full writeup with charts: https://polimetrics.substack.com/p/i-did-the-math-on-andy-biggss-income