As a GSoC mentor, I just received an email from Google about how to retain volunteers, and here is their main tip:
The orgs that have been most successful in keeping their GSoC students as long term contributors to their project have encouraged their students to become maintainers on their projects and make it clear they have ownership of a particular area of the project.
Question: Is there hard evidence (or statistics) that giving a volunteer ownership of a specific area benefits an open source project?
Successful and unsuccessful examples of this strategy are also welcome.
Context if needed: Our project is a single Android app, in a single GitHub repository, a large user base with many beta testers, about 10 regular developers and 1 GSoC student.