Do students exhibit rational behavior in determining study time? While I teach some economics classes, I must admit to near complete ignorance on the optimization processes students undertake when studying.  We often say that the "best" students are those who earn the highest grades.  However, from (naive) economic first principles, a rational student might be expected to endeavor not to maximize her grade, but rather to study until the marginal benefit of additional study equals its cost.  Thus, we view students as grade producers who transform labor into grades. 

Have there been any studies that investigate the optimization problem these "grade producers" are solving when they choose how much to study (and especially on how they assess the benefits of grades)?
I think this is a very interesting question that I'm not sure we know the answer to. As we move towards online-based instruction, the question of whether students "optimally" determine their study time is extremely relevant. For instance, if students are allowed to "self-pace" themselves, will they do so optimally? Going to lectures in part may serve as a "commitment device" to go to class. 

The only good economic study I know of is by David Figlio et al "Is it Live or is it Internet?: Experimental Estimates of the Effects of Online Instruction on Student Learning". It also has the virtue of (attempting) to be a randomized controlled trial. However, I'm sure that there are probably other behavioral economics or psychology studies worth visiting.

The authors write,


  "Without the nudge of having to attend classes, the authors suggested,
  it can be easy to let recorded lectures pile up unwatched. Indeed, it
  is common at Florida to see students in libraries cramming viewings of
  a dozen lectures back to back before exams."


Here is a link to the paper (gated, unfortunately):
http://www.nber.org/papers/w16089

Also a popular press description:
http://www.nytimes.com/2010/11/05/us/05collegeside.html