What are the implications of Techstars under-reporting the deaths of their startups? Not to knock 100K in notes (and the other benefits of being in a reputable accelerator) but these statistics vastly overstate the positive impact of Techstars.

As for Crunchbase, they could do a reasonably good job of catching the death of startups by running a check every six months for basic social media updates. While it might be premature to call a quiet startup dead, they could include a line to call a startup "inactive."