Dating by the numbers

What if the hookup culture and the decline in marriage have little to do with women and almost everything to do with men? What if the fact is there just aren't enough men?
According to Fortune contributor Jon Birger, a "lopsided gender ratio" helps explain some of the quirks of the dating world, such as why so many gorgeous women are rarely asked out, or why many men seem to have no problem finding a partner while many females are unhappily single.