Evaluating AI coding agents one at a time on isolated tasks misses the real problem: agent contributions create twice as much integration friction in shared codebases, making ecosystem-level governance more important than agent-level performance.
This paper studies how autonomous coding agents affect shared software repositories by analyzing over 930,000 pull requests. It finds that integration friction—the cost of merging code when others are changing it simultaneously—is largely a repository-level problem, not an agent problem.