The study released Tuesday by the conservative-leaning Pioneer Institute says the proposed 4 percent surtax combined with a recent federal tax change would effectively double the annual state income tax paid by Massachusetts' highest earners to $318,000.
The new federal tax law caps deductions for state and local taxes at $10,000.
Supporters of the ballot question that seeks to boost revenue for transportation and education dismiss the notion that wealthy residents might flee the state.
A recent study by Massachusetts Budget and Policy Center found the wealthiest 1 percent of taxpayers would pay on average $84,000 less in federal taxes next year because of the new U.S. law.
Copyright 2018 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.