These are not only shorter, they're easier to write. They're easier emotionally and psychologically and when you're trying to write you have to be very careful of your own psyche because it can be very disruptive. You can be very unhappy and nervous when you're writing. You can also be very anxious, but this can be a sign that the writing is important. But if you're too anxious and you can't sleep, which has happened to lots of writers, then that can be too disruptive.
Oates is known as a hugely prolific writer.
Often she will release one novel a year, and a collection of short stories, and occasionally throw a pseudonymous novel into the mix too. Well, I don't seem very prolific to myself. It seems like I'm always revising. I write fairly slowly, I write a paragraph then I look at it and write it over again. I spend a lot of time daydreaming and thinking, and trying to get the structure of the work like a movie in my head.