Really, I could have done with remembering in which Times' edition the article was in and copy and pasting it here - but the basic premise is that authors should not be writing outside their own experience. I.e. If you're white, you shouldn't be imagining black experience. I expect this is ditto everything else you as a writer might not be: any other nationality bar your own/ your gender/ your age/ your income/ class/ disability and whether or not you're an elf/ alien/ animal. Discuss!