WASHINGTON » THE ISSUE: In much of the U.S., families spend more on child care for two kids than on housing. And if you’re a woman, it’s likely you earn less than your male colleagues even though 1 in 4 households with kids relies on mom as the sole or primary breadwinner. That’s according to the latest research that suggests while the U.S. economy has improved, women and their families are still struggling to make the numbers work.

It’s already illegal to pay women less for the same job or deny them a raise because of their sex, and the pay gap has narrowed dramatically in recent decades. Republicans say tougher regulation would only hurt U.S. businesses — costing Americans jobs — while new taxpayer programs would drive up the deficit.

Democrats say it’s still too easy for employers to hide or deny wage disparities because workers rarely perform identical jobs. And with paid leave scarce and expensive, women and their families are losing out on wages that could be reinvested back into the economy and keep struggling families off government aid.

WHERE THEY STAND

Hillary Clinton calls for 12 weeks of government-paid family leave to care for a new child or seriously ill family member, which she says would be paid with higher taxes on the rich. She also backs legislation that would force private businesses to disclose gender pay data to the government for analysis; the bill would allow women to seek punitive damages for discrimination.

Donald Trump has said he thinks the pay gap isn’t an issue. He’s called for allowing parents to deduct the “average” cost of child care from their taxable income if the parents earn under a certain, unspecified amount. But what about the 40 percent of Americans who don’t earn enough to pay federal income taxes? Trump’s campaign says lower-income workers would be able to exclude childcare expenses from half of their payroll taxes.

WHY IT MATTERS

This issue isn’t going away. According to the Bureau of Labor Statistics, women are about 57 percent of the labor force and many are mothers of young children. More than half of mothers with an infant under age 1 have paid jobs, for example. And that number climbs to 74 percent among moms with children under age 17.

Yet the bureau says women in 2014 working full time earned 83 cents on average for every dollar a man makes. Why? The Pew Research Center says women are much more likely than men to take time off work or reduce hours to care for family members.

But remove those factors and the pay gap persists. The American Association of University Women found that female engineering majors earned 88 percent of what male graduates did one year after school. Another study, by the University of California, San Francisco, found that male nurses out-earned female nurses by as much as $5,000 a year, even when taking into account years of experience, location and specialty.

Aggravating wage disparities is the steep cost of child care. Families in 2011 paid on average $143 per week for child care — up from $84 a week in 1985 (in constant 2011 dollars). According to the National Conference of State Legislatures, child care costs for two kids are higher than the median rent payment in every state. And only 12 percent of private industry workers last year had access to paid family leave, despite strong public support for it and concerns in some states that struggling parents are turning to low-quality, unlicensed daycares because they are cheaper.

For Clinton’s anti-discrimination proposals to work, she’ll need Congress and state legislatures to jump on board — no easy task politically. U.S. businesses have already staved off legislation by warning that a new law would expose them to frivolous lawsuits.

Meanwhile, Trump’s child care proposal does nothing to address the pay gap.

This story is part of AP’s “Why It Matters” series, which will examine three dozen issues at stake in the presidential election between now and Election Day. You can find them at http://apne.ws/2bBG85a.