Econometrics is the application of statistical methods to the study of economic data and problems. In the area of competition and regulation, econometric analysis is often used to provide justification for regulatory proposals and decisions. Yet figures are not infallible and mistakes can happen for a number of reasons. This can have real ramifications for businesses that are being regulated. This new bulletin from Frontier Economics, Quantitative analysis - quality assured? uses recent actual examples to show the importance of using appropriate methods, and why it is critical to carefully review the analysis before drawing conclusions from the modelling results.