There is a fundamental value in assessing the effectiveness of regulation once it is in force. It is only after implementation that the effects and impacts of regulations can be fully assessed, including direct and indirect incidence and unintended consequences. Regulations may also become outdated as the result of a change in societal preferences or technological advancement. Consequently, regular reviews are needed to ensure that regulations are still necessary, relevant and fit for purpose. Evaluation of regulations is mainly carried out ex ante through the Regulatory Impact Assessment process while ex post evaluation remains the least developed of the regulatory tools. Administrative simplification, on the contrary, has been widely used both in OECD and LAC countries. It encompasses the reduction of administrative requirements to comply with regulation and moves from a simple review of norms to the quantification of the administrative burdens and better targeting of the simplification efforts.