A key provision in next year’s looming debate over the possible extension of the Tax Cuts and Jobs Act highlights one of many examples of gender bias in taxes, according to experts.

The current SALT deduction limit of $10,000 for state and local taxes saves taxpayers between $79 billion and $118 billion per year in lower expenditures. It will play a pivotal role in the discussion about TCJA provisions set to expire after 2025 because it’s one of only a handful that lower the price of extensions projected to cost $4.6 trillion. 

Critics have referred to the limitation as a “marriage penalty” and called for raising that ceiling or eliminating it. Others reject that idea on the grounds that the deduction primarily benefits wealthy households in high-tax states such as New York and California.

READ MORE: The 12 firms with the largest percentage of women advisors

One of the “presumably unintended further consequences” of the limit has been discouraging the so-called second earners in a couple, who are often women, from working due to the higher potential taxes on combined income and restrictions on the deduction for state and local duties, said Jennifer Bird-Pollan, a law professor and the Alan S. Schenk Chair in Taxation at Wayne State University. She gave a presentation on the gender implications of the curb on the deduction this past fall at the American Tax Policy Institute‘s Gender and Tax Symposium. 

While the tax policy isn’t likely motivating people’s decisions about whether to get married or “dramatically impacting” a spouse’s decision not to get a job as the lower-earning member of the household, the restraint on the deduction amounts to “a further thumb on the scale in the same direction, without any conversation on whether it was appropriate or not,” Bird-Pollan said. The taxes enter the equation alongside other potential costs such as childcare, commuting, dry cleaning and food preparation, she pointed out in an interview.

“Those are all costs you incur if you decide to work outside the home. The salary has to be high enough so that you’re not actually worse off,” Bird-Pollan said. “The tax bill is just going to be that much higher if they’re not allowed to deduct their state taxes.”

Other areas reflecting gender bias in taxes play out in the form of “tampon taxes,” classifying menstrual products as luxury items subject to sales duties; differences in the value of Social Security benefits for women, who tend to be paid lower wages and live longer than men, as well as the rules for getting the maximum spousal payments; the treatment of paid surrogacy; and the disparate impacts of the child tax credit, the earned income tax credit and savings from capital gains, according to Bridget Crawford, the organizer of the conference as the vice president of the institute and a law professor at Pace University’s Elisabeth Haub School of Law.

READ MORE: 10 big trends in SALT for 2024 

The conference in Washington, D.C., drew about 110 attendees in person and virtually among academics, policy experts and government officials, she noted in an interview. It followed the institute’s conference two years ago about racial disparities in taxes and came before another one this March on tax law, the environment and climate change. The organization welcomes more participation and collaboration from across the tax and wealth professions, Crawford said.

“The tax system is a lens for analyzing our society’s values and choices,” she said. “It’s an excellent starting point for very important conversations that we have had and need to have and will continue to have around all sorts of justice-related concerns.”

In terms of the cap on the deduction for state and local taxes, policymakers could alter the existing policy by imposing the limit on property duties alone or simply boosting the allowable amount for married couples, Bird-Pollan said. Tweaking it or getting rid of it will likely prove difficult, though. 

Democrats don’t often push for “tax cuts for higher-income people,” and they’re in the minority in the House and the Senate anyways, she pointed out. President Donald Trump and his Republican party have the trifecta in Congress and the White House, but they will be facing a complicated challenge from the budgetary effect of extending the Tax Cuts and Jobs Act.

“It gave them some revenue, and it only hurt people in blue states, because those are the states that have those taxes,” Bird-Pollan said. “The Democrats have a little bit of a hard time arguing this. If it changes, it’s going to be because of Republican legislators from high-tax jurisdictions.”

READ MORE: Why is the pay gap for women financial advisors so wide?

She credited Crawford’s work with encouraging many states to end sales taxes on feminine hygiene products and noted that financial advisors and tax professionals can read forthcoming research from the conference in legal journals. Exploring the gender bias in taxes can often begin “when we acknowledge things like women are still paid less than men,” Bird-Pollan said.

“If that’s true, then let’s think a little bit about whether that’s a fact that we’re comfortable with or whether particular changes are making that worse or easing that a little bit,” she said. “We just need to think about where these costs fall and whether, as a society, we’re comfortable with where they fall and whether we’d like to see that changed.”