Alison Griswold:

How did Uber’s ratings become more inflated than grades at Harvard? That’s the topic of a new paper, “Reputation Inflation,” from NYU’s John Horton and Apostolos Filippas, and CEO Joseph Golden. The paper argues that online platforms, especially peer-to-peer ones like Uber and Airbnb, are highly susceptible to ratings inflation because, well, it’s uncomfortable for one person to leave another a bad review.
 The somewhat more technical way to say this is that there’s a “cost” to leaving negative feedback. That cost can take different forms: It might be that the reviewer fears retaliation, or that he feels guilty doing something that might harm the underperforming worker. If this “cost” increases over time—i.e., the fear or guilt associated with leaving a bad review increases—then the platform is likely to experience ratings inflation.
 The paper focuses on an unnamed gig economy platform where people (“employers”) can hire other people (“workers”) to do specific tasks. After a job is completed, employers can leave two different kinds of feedback: “public” feedback that the worker sees, and “private” reviews and ratings that aren’t shown to the worker or other people on the platform. Over the history of the platform, 82% of people have chosen to leave reviews, including a numerical rating on a scale from one to five stars.