Women’s advocates in Boston want the Massachusetts State House to do more to ensure women receive “equal pay for equal work.” A press event earlier this month mostly celebrated proposed legislation to increase penalties for businesses violating equal pay statutes and further regulate compensation practices, but some women leaders recognized that laws alone cannot eradicate the wage gap between men and women.

Megan Costello, director of Boston’s women’s advancement office, was quoted in the NewBostonPost explaining: “It’s not just up to government, it’s not just about legislation…. This has to be a collective effort – of government, of business, of the nonprofit world, of individual citizens – because we do not do this alone.”

Costello is right. Legislation like that proposed in Massachusetts is unlikely to do much to eradicate earning differentials between men and women. After all, laws already exist outlawing businesses from paying men and women differently for performing the same work, as well as protecting workers who discuss their salaries from retaliation. The new legislation would expand the definition of equal work to include men and women who are in “substantially similarly” positions, but even this may not end up being the hoped for boon to women. Businesses facing new red tape and the potential for lawsuits may seek to consolidate their workforces, lower compensation across the board, and standardize compensation practices, resulting in fewer job opportunities and a less flexible workplace.

Laws against discrimination won’t eradicate differences between men’s and women’s earnings, because most of those differences aren’t caused by discrimination in the first place. Rather, they are the result of the different choices that men and women make when it comes to work life. Children play a big role in this, which leads children’s advocates such as, Marie St. Fleur, to lament: “I don’t think it’s fair, because we all have the babies. So why is it that I have to pay a higher cost?”

It’s easy to complain that women’s earnings tend to go down when they become mothers, but changing that reality requires understanding why this happens. The simple fact is men and women tend to make different decisions about work after having children, and these choices affect how much they earn. The Department of Labor’s Time Use Survey shows that women with children under age 18 at home work fewer hours than women without children. Men go in the other direction: Men with children work longer hours than their childless male counterparts, as well as more hours than women.

It’s no surprise that men who work longer hours also earn more money. Those interested only in someone’s earnings see this as evidence that society’s deck is stacked in men’s favor, but this can also be seen as evidence of men making their own sacrifice for children. Many men give up their free time to earn more to help care for children.

Women’s advocates imply that women are the losers in a scenario where dads work for more and moms work for less, since housework is nothing but drudgery. Yet this ignores that extra hours in the office or on the job aren’t always a joy either. This is especially true for the disproportionate number of men who work in jobs with unpleasant attributes. Men suffer the vast majority of workplace injuries and deaths.  They are more likely than women to work outdoors in the heat and cold, in sewers, on rooftops, hot construction sites, smelly fish boats and refineries, and guarding prisons. Men commute longer to and from their jobs. They are more likely to work overnight shifts.

Why do men take on these unpleasant tasks? A main reason is that they want to earn more money, often to provide for their families. Women, in contrast, generally pursue careers that offer more comfortable work environments, that are indoors, closer to home, with few physical risks, and allow for pleasant interaction with other people.

Who’s being short-changed in this scenario? That depends entirely on your perspective. Feminists can lament that women are being cajoled by society into caretaker roles with lower earnings, but disgruntled men could complain that they are being pushed to risk life and limb, because they are valued only as breadwinners.

Nature and nurture likely both contribute to men and women’s different decisions. Biology surely plays a role, as does society, by sending messages about expectations for the sexes. Certainly we want to create a culture that encourages women and men to pursue their true interests, rather than conform to society’s idea about gender roles. Yet in public policy discussions about ways to eradicate the wage gap, it’s important to understand all that would have to change to make that happen: Women would have to commute longer, work more hours, take more physical risks and pursue very different careers than we do today.

Perhaps women will move in that direction. But more likely many won’t. Women are likely to continue to prioritize job attributes other than pay and allocate more of their time to their families. As long as women are freely making these decisions, then the “wage gap” isn’t a problem that government can — or should — try to solve.