Dr. Snitkovsky acknowledges that he approached the research with skepticism about tipping.

"I came to this study with a bias. Personally, I don't like this practice, and I wanted to understand what drives it. First of all, tipping puts customers in an uncomfortable position. Studies have shown that tipping can encourage sexist behavior toward female servers -- who may refrain from setting boundaries to avoid losing tips. Other studies demonstrate that people tend to tip more generously when a server is of their own ethnicity, introducing an element of racism. It's easy to find good reasons to do away tipping, but the custom also has some positive effects, making it a complex phenomenon. Ultimately, tipping allows those willing to pay more for the service to do so, thereby subsidizing the service for others. That's a positive aspect. Additionally, tips do seem to encourage servers to provide better service, even though this effect is very limited. In my opinion, in the 21st century business owners have better tools to assess server performance, such as online reviews and even in-house cameras."