When I worked in software engineering we have a female worker complain that she and a male worker had started on the same day but after about 7 years she was making less than the male. She had to be reminded that she had taken three 1-year leaves of absences when her children were born, and thus had 3 years less experience.
Also, when the clock struck 4:30 she left, period. Most of us stay later. During crunch times I'd go home at 6 PM, get something to eat and be back by 7 PM and stay until 10 PM. Then start all over the next morning at 7 AM. These things do in fact affect your salary.
That 72% myth has been around for at least forty years. Rad feminists and lib pols repeat it endlessly, but it doesn’t make it any less false. It’s still fundamentally a dishonest statement. The “experts” think Romney was right not to mention the myth because it might turn off female voters. I don’t understand how telling the truth about something would turn off voters.