“The summer movie machine is in full swing, and, once again, it’s almost impossible to find a studio film with a woman at the helm during the season that provides more than 40% of the year’s box-office revenue. According to Media by Numbers, all 30 of the 30 top-grossing films from last summer were directed by men. According to my informal survey of major studio films from this summer, only two — “Mamma Mia!” and “Sisterhood of the Traveling Pants 2” — are directed by women.”