||This thesis analyzes the topic of economic methods applied in regulatory impact assessment (RIA). The sense of a RIA system, assumptions of its effective functioning and its place in the framework of the EU's and Czech Republic's legislative process are introduced. Economic methods often used within the regulatory impact assessment process are discussed. The thesis empirically examines the progress in RIA methods quality between 2008 and 2011 in the Czech Republic and determinants of RIA methods quality are identified. We come to conclusion that the quality of RIA methods in the Czech Republic grows with expected costs of the regulatory policy and in case of RIA carried by an external subject.