An excellent new video resource was showcased at reKindle and at Synod 2012 in June which deals head on with the question about why today's young adults are leaving the CRC. It was written and produced by young adults, and it's well done.
You can see the movie trailer on YouTube. Here is the link: http://www.youtube.com/watch?v=C-qJHnUiqas
This will be a must-have resource for every congregation struggling with the loss of their young adult members.
There is more info available right now at http://yalt.crcna.org/shift-film/ (which is the CRC's Young Adult Task Force page).