The restructuring of electricity industry towards a competitive market has resulted in essential changes at the operation of power market. This book illustrates the results of research work made as intersection between technique and economy. Cornerstones of this work are carried out in the fields of congestion and power system fixed costs. A contribution to the study of power losses cost is also included in this book. Considering the system congestions as a main reason for price volatility the book presents a method for the allocation of congestion component of nodal prices for energy to the market participants. Furthermore, a new method for the simulation of zonal pricing using nodal pricing algorithm, in order to assess the Norwegian market, is given. The last part of the book deals with the task of power system fixed cost allocation. For this purpose, game theoretical methods are used.