DEAR MR. DAD: My girlfriend and I are about to become parents. She wants to get married before the baby is born, but I don’t really see the point. Can’t unmarried parents be just as committed as married ones?

A: Given that so many children are born to unmarried-but-living-together couples, I’ve always maintained that it’s more important to support fathers – whether they’re married or not – than to make judgments about people’s lifestyle choices.

I still believe that’s true. However, there are a few compelling reasons you might want to give some serious consideration to getting married:

• Unmarried fathers aren’t as involved. “Cohabiting partners, even if they are biological father to the child, do not invest the same amount of time with children as married biological fathers,” says family studies researcher Sandra Hofferth.

• In cases of divorce, mothers have primary or sole custody of the children about 80 percent of the time. While divorced fathers frequently feel cut off from their children’s lives, unmarried fathers have fewer legal rights and find it even harder to maintain a strong relationship with their children after the breakup.

• It’s good for your health. Researchers have found that unmarried couples who are living together are more likely to suffer from depression, and have more health problems than married couples. This may be because “cohabitants put up with behavior in their partners which husbands and wives would discourage, particularly regarding smoking, alcohol and substance abuse,” according to the Institute for the Study of Civil Society.

• It may keep you alive longer. Married men have been shown to have longer life expectancies than unmarried men.

• It’s good for your finances. A number of studies show that married men earn 10-40 percent more than single or cohabiting men.

Despite all of this research, no one has a solid idea of why being married makes such a difference. But the connection seems to be there. One last thing. As long as the topic of marriage is on the table, consider doing it sooner rather than later. The longer a couple lives together before the wedding, the more likely they are to get divorced later on.

Armin Brott is the author of many best-selling books on fatherhood.

His new DVD, “Toolbox for New Dads,” has just been released. Find resources for fathers at www.mrdad.com or by emailing arminmrdad.com. Try DaddyCast, his new, twice-weekly podcast (http://www.mrdad.com/daddycast).