Economics of forgetting I'm interested to know economic justifications of forgetting in various fields.

On example is Green and Porter(1984). To sustain a Cartel, Cartel members have incentive to forget deviations in a sufficiently distant past.

Another is Ekmekciy(2011) which shows that a rating system works better if it stops publicize misconducts, once they're old enough.

Literature on a more abstract level is also welcomed, e.g. results like it's more socially desirable in a dynamic games, some agents are restricted to stationary strategies.
Maybe not what you are looking for, but a related concept is regret. Orphanides and Zervos (1995) is a classic paper on rational regret in a health economics concept http://www.jstor.org/discover/10.2307/2138580?uid=3739840&amp;uid=2&amp;uid=4&amp;uid=3739256&amp;sid=21106216442271 

There's also plenty of irrational regret papers, mostly just boiling down to hyperbolic discounting models.