Reputation Inflation, by Apostolos Filippas, John J. Horton, and Joseph M. Golden
Great paper showing how perceived relative costs to rating systems can loop into system lower effectiveness. As raters react to incentives to report public rating, bias is introduced and can lead to a rather boolean outcome: anything different from perfect score is serious statement of reproval.
This at first may be seen as a problem. However, those proposing rating mechanics may in fact use such bias to get a stronger grip on those being rated.