Has anyone done any research on what makes former believers drop religion?

I recently came across this, from the theist perspective (i.e. they tracked down people who had left and interviewed them, with the hope to prevent that in the future), and I remember it hinged mostly on social factors. (The enthusiastic youth pastor quits, and is replaced by someone that doesn't know the Bible as well, etc.)

I'm sure there are some people who deconverted because of reading those books- but it's likely that they also would have deconverted if they moved from Town A to Town B, for example, so that doesn't seem like a terribly effective way to reach everyone.