Some authors say that they tend to overwrite on the first draft. When they go back through to edit, much of the task consists of trimming out the excess, cutting bits that aren’t necessary, tightening up the wording, getting to the point. When they’re done, the resulting draft is shorter.
For me, it is the opposite. I write my first draft, I find many parts that aren’t described well enough, that need to be fleshed out more, things that need to be described or explained better. Almost invariably my stories tend to grow longer as a result of editing.
What about the rest of you? Do your stories tend to grow or shrink when you edit them?