Exploration: Why do lesbians earn more than heterosexual women?

Statistics show that lesbians earn more than heterosexual women, but why?

In some surveys of the past, even taking into account factors like race, education, occupation, location and even number of children, lesbian women still earn about 6% more income than heterosexual women. There are a lot of theories to explain this, but eventually all point to one thing: men. In a family, it is naturally expected that men earn more. When someone has to sacrifice their career for the family, most women would step forward, which leads to less investment in careers by heterosexual women than men in general American households.