Let me give you an example: reputation can solve the 'market for lemons'.
If you build a reputation for honest dealing and high quality, then people can trust that you don't sell them lemons (ie bad used cars in the original example). This reputation is valuable, so (most) companies will try to protect it.
And that's exactly what's happening with some used car dealers.
I think you should read the paper. Did they exclude reputation or did reputation not matter to the equation? Are you going to criticize the fact that they "excluded" the color of a person's eyes?
If you build a reputation for honest dealing and high quality, then people can trust that you don't sell them lemons (ie bad used cars in the original example). This reputation is valuable, so (most) companies will try to protect it.
And that's exactly what's happening with some used car dealers.