When real estate agents sell their own homes do they make more or less than when they sell clients homes? Why is that?

The book argues that real estate agents typically sell their own houses for more money than their clients' houses. We need to consider that the agent would save money on commission. One also has to regard that an agent's house might be of more value than the typical client's house.

A licensed real estate agent / broker can sell his own house. Contractually, it has to be disclosed in the contract and the MLS that the seller is also the listing agent.