“It was the first time I can recall experiencing the best kind of writerly jealousy—the kind that made me marvel at another writer’s work and strive to meet that standard in my own writing.…That kind of envy is a gift. It motivates, pushes, drives. It gives way to action rather than negativity and despair.”
There is an excellent post on writers and jealousy by Laura Maylene Walter over on the Kenyon Review blog. I think all writers should read it and recognize the beauty and ugliness of their writing-based envy.