This book aims to address the issues of power system optimization from a microeconomic point of view. It is well known that the optimization in power system planning/operation and electricity markets is not a new area. Recent advances have attempted to focus on the application of microeconomics and game theory to the optimization of power system. The state of art of literature still has not addressed the issue with a systematic investigation. This book attempts to summarize the research outcome of the application of microeconomics and game theory and related approaches to power systems and electricity markets.