Some days, Jennifer Hoese of Watertown, Minn., struggles to get to work on time, a common challenge for many working folks.

But Hoese -- like many of the nearly 16 million U.S. working women in her shoes -- fears her lack of punctuality might be attributed to just one cause: that she's a mother.

"It's assumed that for mothers, family always comes first," said Hoese, who often has trouble scooting her 2- and 3-year-old daughters out the door. "But you know what? It does."

Hoese maintains that having to "do it all" has made her a better worker because she's more efficient. But she admits that keeping the peace at home without missing a beat at work isn't easy, particularly in a bad economy where many employees are already on edge.

To add to the stress, recent studies show that working moms are paid less than their childless counterparts. Experts say docking working moms is as outdated as assuming that it's always the mom who stays home with a sick kid or drops off a forgotten lunch.

"Traditional roles of parenthood have changed dramatically," said Erin Kelly, an associate professor of sociology at the University of Minnesota. "But there's still a deep-seated culture that mothers are the ones that are staying home with the kids. And it comes out in unconscious decisions from employers.

"They believe mothers are less committed to their jobs."

Women who are on the lower end of the pay scale are the ones who pay the highest price, said Kelly. "You may have to decide: Am I going to go home and meet my kids at the bus stop and risk getting fired, or am I going to leave my kids and stay as I've been told to stay?"

But white-collar moms share the pain. "People think we always have sick children, that we have too many responsibilities, and you know, that we're not 'career women,'" said Lynn Lasser, who works in private investment in Minneapolis and has two grown children.

"I can't tell you how many times my kids probably went to day care and shouldn't have been there, because I was like, 'Omigod, I can't miss another day of work.'''

In Lasser's experience, little has changed over the years. "I have a 33-year-old daughter with a young child, and it's absolutely unbelievable what her superiors will say to her [at work]," she said. "I feel terrible, because it brings back all those terrible memories."

The mommy track

In a study published last month, researchers at the University of Massachusetts in Amherst found that the salaries of women of all income levels dip when they have children. According to the study, the earnings penalty ranges from 15 percent per child among low-wage workers to about 4 percent among the highly paid.

That follows an earlier study by Stanford University sociologist Shelley Correll, who found that mothers looking for work are less likely to be hired, are offered lower pay (5 percent less per child) and that the pay gap between mothers and childless women under 35 is actually bigger than the pay gap between women and men.

Correll also found that mothers are perceived as less competent, less committed and less dependable than their childless peers, and that the "cultural understandings of the motherhood role exist in tension with cultural understanding of the ideal worker role."

In the workplace, that can mean that if a parent needs to leave for an emergency, their co-workers might feel they're shirking their responsibilities. Worse yet, the co-workers feel they have to pick up the slack.

"In some work groups, that does happen," said Patricia Dougherty, vice president and principal consultant of the Weston Group, a human resources law and consultation firm in Minneapolis. "There are just different cultures and work styles" between working moms and childless women.

But Kelly said just about everyone has times when they're distracted at the office. "I've seen people plan weddings, go through divorces, something where for some period of time people's energies are split. I think most people are capable of juggling things in their lives and still performing very well on the job."

Stereotypes stick

The discrepancy in pay is likely rooted in outdated perceptions of working moms that aren't changing with today's evolving family, experts say.

"Because our cultural assumption is that all women that are mothers are going to need to prioritize family responsibilities highest, those penalties are going to affect mothers," said Kelly. "Unfortunately, they also hit women that don't have heavier workloads at home, who have organized their lives around work, who are capable of working a 60-hour week."

A poor economy has fueled a move away from the traditional "Leave It to Beaver" family. In the current downturn, more than 80 percent of initial layoffs involved men. That's likely to translate into dads taking responsibility at home and easing the pressure on moms.

But while more men may be bringing up babies, unlike women, they're rewarded for it. According to research done by New York University's Rebecca Glauber, working men who have children receive a "wage premium" of as much as 9 percent more than childless men.

The assumption there, said Kelly, is that men who become fathers must provide for their families, which makes them better employees. Women with children, on the other hand, are assumed to be worse employees, because their main role is to take care of the kids.

"There's still this underlying thing, and it comes out in these often unconscious decisions from employers that they believe mothers are less committed in their jobs, " Kelly said.

In one of the Stanford studies, Correll presented employers with mock evaluations of female employees. All the measurable characteristics (timeliness, efficiency, etc.) were the same in the evaluations. The only variable was the motherhood status. Correll found that employers consistently judged the mock mothers more harshly, viewing them as less committed and less competent than childless women.

"If someone asked them, 'Do you view mothers differently?' of course they'd say no," Kelly said. "And they might not even evaluate someone they know that way. But when it comes to snap judgments -- in hiring and promotions -- those expectations are still at play."

Dougherty warns that some employers, particularly those in small companies that have made heavy cuts in human resources, might not even realize that such discrimination is illegal. "They don't know how to handle employees missing work for their families and they say, 'Should I just fire them?' and I say, 'Oh, gosh, don't do that.'"

Like many working mothers, Hoese finds the lingering stereotypes and pay discrepancies discouraging, but said, "I don't have time to fight that fight. I have so many balls juggling in the air that if one falls, everything falls to pieces." She added: "I hope someone will."

Amelia Rayno • 612-673-4115