You ask your brother to check in with his buddy. As luck would have it, he still as the essay on his hard drive! He recalls having done pretty well on it and the essay question hasn't changed at all! He sends it to you, you slap your name on it and hand it in!
This is even worse than buying the essay! At least if the student bought the essay, there would be a skim of the paper to make sure that it at least fit the question. Here, there is less motivation to even do that. The student has learned nothing and may have even asked the brother's friend for the rest of his folder for that subject to cover him for the rest of the course preempting even more learning down the road.
The discussion around this type of student response to an assignment often becomes about preventing or punishing plagiarism. Or a teacher might come to the realization that maybe they need to have a handful of questions that they rotate through to decrease the chances that this would happen. The real discussion needs to be about the question itself. Why are we dictating the question in the first place? If there is a real reason to dictate the question, is there a way of phrasing the question that makes copy and paste answers more difficult? Can we get students to personalize their response in some way that would make each essay unique? Is there a way of sharing the responses in a way that makes the student more accountable for their own learning or allows them to reflect and build on what they've learned through their essay?