Econometrics is a branch of economics that combines economic theory, mathematics, and statistical methods to analyze and quantify economic relationships. It involves the application of statistical techniques to economic data in order to test economic theories, make predictions, and inform policy decisions. Econometric models are used to estimate and measure the impact of various economic factors on outcomes of interest, such as the effect of education on earnings or the relationship between inflation and unemployment. Econometric analysis often involves the use of regression analysis, time series analysis, and other statistical methods to analyze economic data.