If I initiate and/or pitch an idea, the topic comes first, followed by research to make sure it’s a viable idea. But a great deal of my writing comes from editors who send me ideas, knowing that I can do the necessary research and pull the story together. Not everyone enjoys this kind of work — particularly in my primary field, which is travel writing. I think it’s definitely the research that has sustained my career.
You could assign the same topic to five writers and the one who does the best research will almost always come out on top, unless they can’t write for crap. That’s a whole other story, though, right?