The country where every family wants a boy

In a certain country every family follows the same rule: keep having children until you have a boy, then stop. Each birth is a boy or a girl with equal probability, independently of everything else.

Someone argues: "Families with girls keep trying, so there will be lots of girls. Families stop as soon as they get a boy, so boys are rare. The population will be mostly girls."

Is that right? In the long run, what is the ratio of boys to girls among all the children born?