Movie studios and directors have come up with a lot of dumb excuses for not casting people of colour in movies over the years. There aren't enough black stars who are a draw at the international box office! Women don't find Asian men hot! Those people don't try out for these kinds of roles!
There are enough obvious evasions and attempts to excuse laziness, unconscious bias or outright racism that it's tempting to view every single explanation for why a white actor has a particular role as dishonesty.
But some of these excuses are worth listening to, not because they excuse white actors getting jobs that actors of colour might have wanted to compete for, but because they tell us more about what it's going to take to make Hollywood a more equitable place.
Take Doctor Strange, which has roused fans' ire for turning the Ancient One, the titular character's (Benedict Cumberbatch) teacher, from a Tibetan man into a Celtic woman (Tilda Swinton) who for some reason teaches in a Tibetan fortress.
Maybe Marvel just really wanted to cast Swinton - who to be fair, oozes engimatic authority - and the whole mishegas is an example of the way Hollywood seems to create opportunities for women or people of colour, but not both at the same time.
But C. Robert Cargill, who wrote the movie, had another explanation: He said in an interview the concern was that having a prominent Tibetan character in the movie might make it harder for Doctor Strange to get access to Chinese audiences.
If Cargill's summary of China's relationship to Tibet didn't quite capture all the nuances of this particular piece of geopolitics, he's not wrong that when it comes to the movies, things in China are complicated.
In 2012, the United States and China reached an agreement that would allow an additional 14 foreign movies into China, up from the 20 previously allowed.
Those additional movies must be either in 3-D or exhibited in IMAX formats, which means that action movies, which are often already tailored to be screened that way, have an advantage when it comes to getting access to this increasingly lucrative market.
But 34 movies is still not very many. As of last October, the Chinese government hadn't implemented the part of the agreement that would allow another distributor to bring foreign movies into China.
And the road to becoming one of those lucky movies isn't always clear. As the Motion Picture Association of America wrote to the staff of the United States Trade Representative last fall, China's censorship practices are "opaque, unpredictable and slow and can often result in de facto discrimination against foreign content."
All of this is a long way to saying that if Cargill, Doctor Strange director Scott Derrickson, Marvel and Disney were overly cautious about anything that might prevent the movie from being screened in China, they weren't insane to be so.
And invoking Chinese sensitivities about Tibet is a shoddy excuse for racism. They - and all filmmakers who rely on overseas box office - are operating in an environment where President Xi Jinping says things like "Chinese art will further develop only when we make foreign things serve China."
Obviously, the circumstances surrounding Doctor Strange are highly specific. But anyone who wants to see more actors of colour on his or her movie screens needs to seriously reckon with the role the international market plays in Hollywood decision-making.
In 2014, the Ralph J. Bunche Center for African American Studies at UCLA released a report that suggested that movies where between 21 percent and 30 percent of the casts were made up of people of colour performed better than films with casts that were 90 percent white.
That number has become a popular talking point, and with good reason: It adds an economic argument to the moral case for proportional representation in Hollywood.
But what happens when studios believe they're facing a choice between casting an actor of colour and getting access to one of the biggest movie markets in the world? Sometimes, they'll be wrong. But not always.
The fight for equality in the movie industry might be a matter of making Hollywood live up to the American values it claims to represent so well. But the barriers to equality, and the solutions it will take to remove them, require us to take a clear-eyed look beyond our own borders.