Reading and drop-outs study

For every 100 ninth-graders, 68 graduate on time, and 40 of those go to college. But by the following year, 13 of them have dropped out. To a large extent, these behaviors are correlated to reading habits.
National Center for Public Policy and Higher Education. (2004). Educational pipeline loss rate. San Jose, CA: Author.
http://www.highereducation.org/reports/pipeline/loss.shtml

(Note: older study but still relevant...)