WASHINGTON — The framework that Republican leaders released last week to simplify and lower federal income taxes to boost the economy appears to be a mixed bag for Long Island and raises some significant questions, local economists and business leaders said.

Long Island’s wealthy and some middle-class filers, many small businesses and large corporations would get tax cuts, but many homeowners could see taxes rise with the loss of much-valued deductions. And that could bring some negative effects to the local economy.

That’s an initial assessment by local experts of the blueprint that President Donald Trump introduced on Wednesday and that the Republican-controlled Congress will begin turning into legislation amid partisan struggle over the next few months.

“All people favor tax cuts. But we could be in a situation where many people end up paying more,” said economist Herman Berliner, dean of Hofstra University’s business school. “And what are we doing long term for inflation? What are we doing for the national debt?”

The proposal, which Congress certainly will change as it turns this framework into legislation, has some key principles.

It would lower the top corporate rate from 35 percent to 20 percent and tax only domestic profits. It would put a 25 percent top rate on entities such as LLCs and S corporations used by small businesses, many of which now pay higher individual rates now.

advertisement | advertise on newsday

For most taxpayers, the proposal’s core is the simplification of taxes by collapsing the current seven brackets — which range from 10 percent to 39.6 percent — into three brackets of 12 percent, 25 percent and 35 percent, with a possible fourth for high-income filers.

How those streamlined brackets will affect Long Island taxpayers cannot be determined — the framework did not include their income ranges.

But a review of the IRS 2015 taxpayer filing data for Nassau and Suffolk counties, and interviews with experts offer a glimpse of who might benefit or lose from the framework.

What happens to my tax deductions?

That is a mixed picture, said Berliner and other experts.

Everyone would get a bump in the standard deduction, which would be nearly doubled to $12,000 for individuals and to $24,000 for married couples. The child tax credit would get an unspecified boost. And there would be a new $500 credit for non-child dependents.

The proposal also would keep deductions for mortgages and charitable contributions — both claimed by a majority of Long Islanders in 2015.

But in a bid to simplify filings and strip out “tax breaks and loopholes,” the framework ends most other deductions.

The lost deduction that has alarmed businesses, individuals, experts and lawmakers the most would be the scrapping of the deductibility of state and local taxes paid. About two thirds of Long Island filers in 2015 claimed that deduction, for about an average of $13,000.

Berliner called the higher standard deduction and child tax credit hike “a plus.” But he added, “Overall, the elimination of state and local tax deduction will be a major negative.”

advertisement | advertise on newsday

Who gains from ending the AMT and estate taxes?

Nassau and Suffolk counties may be among the wealthiest in the state, but only the top 10 percent of tax filers, and many small businesses, are expected to benefit from scrapping the alternative minimum tax, or AMT. Just a handful of filers will get relief from estate taxes.

That top 10 percent of taxpayers paid nearly $900 million in AMT in 2015. And just 431 of the state’s 9.6 million filers paid estate taxes in 2015, a bill that totaled $1.6 billion.

“The benefits for the very wealthy will be appreciated by the very wealthy and will do nothing for the middle class,” Berliner said.

Will my small business be helped?

advertisement | advertise on newsday

Small businesses with 20 or fewer employees make up about 90 percent of all Long Island enterprises, said Kevin Law, president and CEO of the pro-business Long Island Association, and most of them will benefit from the end of the AMT.

The proposed 25 percent top rate for small businesses set up as limited liability corporations and S chapter firms may help fewer, since many already pay less than that rate with the help of different deductions, said John Rizzo, the association’s chief economist.

“The tax plan could reduce the effective tax rate paid for perhaps 50 percent of small businesses,” Rizzo said.

Will corporate tax cuts help Long Island businesses?

Long Island’s largest corporations are expected to benefit from the lowering of the top tax rate to 20 percent, Law said.

“That is a significant to businesses because, one, they’ll be paying less taxes, and two, they have money to reinvest or diversify,” Law said. “They’ll also have more room to increase wages in a tight labor market.”

Long Island’s largest local publicly traded corporation, Henry Schein, could benefit. It now pays an effective tax rate of 28 to 29 percent. And it has $937 million in profits parked overseas and could take advantage of lower taxes to bring that money back home.

“While we generally support tax reform, it is too soon to say what effect, if any, potential reforms might have on corporations in general and Henry Schein in particular,” the company said in a statement.

Will the tax plan help the Long Island economy?

As it is written now, the plan could actually have a negative effect, primarily because of the elimination of the deduction for state and local taxes, but also because the middle-class tax cut isn’t bigger, observers say.

“Long Island’s middle class is struggling,” said Berliner, who said the Island’s biggest job growth occurs in health care and the leisure industry where workers are not well compensated. “That will not be resolved by this plan.”

Rizzo warned that bigger companies getting tax cuts could create tougher competition for small businesses by expanding and price cutting. And small businesses could be hurt if consumers stop spending as taxes rise from the loss the local tax deductions.

“So whether this tax cut is better for business overall is unclear,” Rizzo said. “It is certainly not a slam dunk.”

Deer Park accountant Herman Ortiz, who has corporate and individual clients, said the framework eliminates a corporate deduction for creating domestic production, so there is no guarantee that tax-cut cash will be used to invest in local jobs and plants.

“Like most proposals, it’s mixed,” Law said. “Whenever you’re reforming the tax code there are winners and losers. While waiting for specifics, there may be some Long Islanders who will benefit and some Long Islanders will be negatively affected.”

But Law added, “All Long Islanders will suffer if we lose the ability to deduct the state and local taxes.”