If New York lawmakers don’t roll back their monster 2021 tax hike soon — or, worse, if they sock the rich with even higher rates — don’t be surprised if state finances collapse.

That was the gist of Empire Center fiscal expert E.J. McMahon’s message to lawmakers last week, and they’d be crazy to ignore him. The 2021 tax bump, aimed at high-income residents, sped up an already worrisome flight of millionaires, he noted, seriously eroding New York’s tax base. Andit’ll only get worse, unless Albany provides relief soon.

Top earners began heading for the exits soon after Washington capped federal deductions for state and local taxes (SALT) in 2018. That move effectively raised New York’s top rate from 5.3% to as much as 8.82% — meaning those with the highest incomes had to fork over over 60% more in state taxes.

The result: By 2020, New York was losing about 6% of its seven-figure residents (those the state depends on most for tax revenue) every year — triple the 2% rate in 2017. From 2010 to 2020, New York’s share of the nation’s millionaires plummeted from 12.7% to 8.9%, though its share of the general population fell only from about 6.3% to 6.1%.

So how did Gov. Andrew Cuomo and fellow Democrats respond? By jacking up top rates even more. In 2021, they passed a $4 billion-a-year tax spike aimed at the very taxpayers already reeling from the SALT cap.

Top rates went from 8.82% to 10.9%, the highest in America (save California). The combined state and city rate topped out at a whopping 14.78%. Factoring in the loss of the SALT deduction, that’s “by far the highest effective rates in New York’s history,” reports McMahon.  

Did millionaires care? Sure seems so, especially for those making $25 million-plus. A whopping 8% moved out in 2021, taking their abundant tax payments with them.

It’s impossible to conclude “that mega-earners are oblivious to higher taxes,” warns McMahon. “This is a danger signal the Legislature must heed.”

To stem the flow, he says, Albany should at least start phasing out the 2021 tax hike — now set to expire in 2027, but history suggests it’s more likely to become permanent — ASAP. At all costs, the state should resist progressives’ mindless push to boost taxes higher still.

Let’s be honest: New York already squeezes the rich — far more than almost any other state, with the top 1% of earners accounting for nearly half of state income-tax revenue (but just 32% of adjusted gross income). If these taxpayers don’t get a break soon, New York won’t have many “rich” left to tax.