Ambitious women who want to maximize their earning potential have two options: don’t have children or find a low-earning husband. That’s the conclusion from a new study out of Harvard, “Dynamics of the Gender Gap for Young Professionals in the Financial and Corporate Sectors.” First things first: this is a study of Chicago Booth MBAs who graduated between 1990 and 2006, so we’re talking about overachievers here — the kind of people for whom “low-earning” is below six figures and long hours are the norm — so these results don’t necessarily apply to the population at large.