Associated Press/ABC, Peter 'Hopper Stone'
In this publicity photo released by ABC, Rico Rodriguez, left, and Sofia Vergara are shown in a scene from 'Modern Family.' The program was nominated for an Emmy award for outstanding comedy series on Thursday, July 19, 2012. The 64th annual Primetime Emmy Awards will be presented Sept. 23 at the Nokia Theatre in Los Angeles, hosted by Jimmy Kimmel and airing live on ABC.

A study from the University of Southern California released this week has joined a chorus of studies extolling a lack of diversity in Hollywood this year.

The USC report found that Hispanics were the least portrayed in Hollywood, with only 4.9 percent of speaking parts in 2013 films. Seventeen percent of films in the same year had no speaking roles for black actors.

The study is at least the third to come out about Hollywood's lack of diversity just this year — UCLA released one in February highlighting race and GLAAD released another last month wagging a finger at a lack of LGBT characters.

While the problem of Hollywood characters being predominantly white and straight is not new, the proposed reasons behind it are greatly varied and hotly debated online.

Think money could be behind the disparity? Not so, as NPR reported earlier this year — the UCLA study found that films with diversified casts actually netted more revenue than those with less diversity.

So what's the problem? Many media outlets analyzing the issue say that the problem lies with the people who control who's hired and who's not, like directors.

Sure, there are few black and Hispanic filmmakers, says Jason Bailey of Flavorwire, but the bigger problem is with white directors that hire monochrome casts. Bailey specifically pointed a finger at Woody Allen and the young filmmakers who follow his lead.

"Too many of (Allen's) much younger contemporaries make the same presumptions in casting: that the default mode is to cast a white actor, bringing in a splash of color only when the story 'requires it,' when their explicitly stated race is 'what’s right for the part.' This isn’t rocket science, dudes," Bailey wrote. "The race doesn’t have to be the point of the character. It can just be a part of the character."

Yet Time writer Lily Rotham pointed out that the problem can extend far from the set and can begin with "industry gatekeepers" like talent agents.

"The biggest agencies have fallen far behind in keeping their rosters of clients diverse, at least racially. Minority actors and creators tend to be represented by smaller agencies, whose clients find less high-profile work," Rotham wrote. "The talent getting through the gate, then, are largely non-minority directors, writers and actors."

Twitter: ChandraMJohnson