Using the Bechdel test*, FiveThirtyEight analyzed thousands of films to determine whether the presence – and prominence – of women had an effect on a film’s box office (emphasis mine):

We did a statistical analysis of films to test two claims: first, that films that pass the Bechdel test — featuring women in stronger roles — see a lower return on investment, and second, that they see lower gross profits. We found no evidence to support either claim.

On the first test, we ran a regression to find out if passing the Bechdel test corresponded to lower return on investment. Controlling for the movie’s budget, which has a negative and significant relationship to a film’s return on investment, passing the Bechdel test had no effect on the film’s return on investment. In other words, adding women to a film’s cast didn’t hurt its investors’ returns, contrary to what Hollywood investors seem to believe.

The total median gross return on investment for a film that passed the Bechdel test was $2.68 for each dollar spent. The total median gross return on investment for films that failed was only $2.45 for each dollar spent.

These two charts from their analysis really say it all:

So, movies that pass the Bechdel test have a better return-on-investment, but the filmmakers working on these films are given less money. What’s up with that? FiveThirtyEight asked the same question:

In the top 100 grossing films of 2012, women accounted for 4.1 percent of directors, 12.2 percent of writers and 20 percent of producers, according to a 2013 study by Stacy Smith, an associate professor at the Annenberg School for Communication and Journalism at the University of Southern California. Of 4,475 speaking roles in those films, 28.4 percent were women. Smith says when more women were involved in the production of a film, it was more likely to have female cast members. In short, when one gender dominates the creative process for a picture, that comes out on the screen.

Bingo. Because women are underrepresented behind the camera, so goes in front of the camera.**

If more women behind the camera means more women on screen which, in turn, means more money made at the box office and pumped into the industry, well, that’s a win-win (not to mention the obvious moral imperative for more equality). Plus, as women fill roles above-the-line in greater numbers, I think you’ll see more below-the-line as well.

* As FiveThirtyEight acknowledges, the Bechdel test isn’t perfect. More on the limitations of the test here.
** The stats are even worse for cinematographers (only 3% were women out of the top 250 films of 2013).