Authors are revealing how much they were paid for their books as part of a Twitter campaign to highlight racial disparities in the publishing industry.

YA fantasy author L.L. McKinney (A Blade So Black) started the #PublishingPaidMe hashtag on Twitter over the weekend, urging authors to disclose the amount of the advances they received for their books.

Authors who participated in the campaign included Roxane Gay, who said she was advanced just $15,000 for Bad Feminist, her blockbuster essay collection, and $100,000 for Hunger, her popular memoir.

“I like my publishers quite a lot but this is why all those corporate statements about diversity are nonsense,” Gay wrote. “A little Instagram post doesn’t make up for racial disparities in everything else.”

Two-time National Book Award winner Jesmyn Ward wrote that she received around $20,000 for her acclaimed novel Salvage the Bones. “Even after Salvage the Bones won the NBA, my publishing company did not want to give me 100k for my next novel,” she said. “My agent and I fought and fought before we wrestled our way to that number.”

By contrast, white author John Scalzi said he received $3.4 million for a 13-book deal, and Emily St. John Mandel revealed that she received an $800,000 advance for her latest novel, The Glass Hotel.

“So #PublishingPaidMe has taught me that white writers can still get a bigger advance for their second book, even after the first book has flopped,” poet JJ Bola tweeted. “Whilst Black writers aren’t even given the opportunity to fail, never mind the struggle of getting an advance in the first place.”

Michael Schaub is a Texas-based journalist and regular contributor to NPR.