Another reason why children of academics, doctors and other professionals are likely to have a better shot is simply the age at which their parents had them. I

Another reason why children of academics, doctors and other professionals are likely to have a better shot is simply the age at which their parents had them. I don't have any data, but I'm sure there aren't a ton of grad students with kids. Having kids when you are young, kind of puts a limit on how much you can devote to your career.