Auspicious Tibetan chatra from 4vector.com
Culture is not an umbrella. So if you're a white writer and you want to write a story in, for instance, Tibetan culture, then asking one person of Tibetan descent is not gaining permission to tell your story. That kind of permission is unattainable.
You can be a responsible writer and do your research, resist stereotypes and get sensitivity-checked. But you'll never get permission.
Permission is an issue with oral storytellers as well, but they take a different view. Like some of my friends who are artists and writers who happen to come from the non-white perspective, storytellers see great benefit in "borrowing" stories. Sharing stories across cultures is the great connecting force of the planet, because it's the shortcut to empathy. Once you've heard a story from the people, you relate on some level to the people.
As Margaret Reed McDonald states in The Storyteller's Start-Up Book, "Now is not the time to freeze all story into pockets of ethnicity. Now more than ever we need each other's stories.
Storytelling is folk art.
We are the folk.
Storytelling belongs to us."