We like this series of articles from Metabeta detailing the findings and insights from a research study carried on more than 170 accelerators.
Part 1: The major challenge for 2 out of 3 accelerators
Part 2: Does industry focus guarantee better deals?
Part 3: Who's fault is it usually when there's little reporting?
Part 4: Is education is essential for incubation AND acceleration?
Part 5: Mentoring beyond bragging rights and looking good.
Part 6: Private Accelerators: Are they performing better?
Part 7: University Accelerators: Are there advantages?
Part 8: Bringing it all together: Accelerator Success Metrics