Regression analysis Econometric models Estimation theory Least squares Heteroscedasticity Mathematical models Linear models (Statistics) Consumption (Economics) Econometrics Autocorrelation (Statistics) Cost and standard of living Error analysis (Mathematics) History Industries Instrumental variables (Statistics) Time-series analysis t-test (Statistics) Apprentices Artisans Asymptotic theory Balance of trade Bayesian statistical decision theory Business forecasting Correlation (Statistics) Economic conditions Economic forecasting Economics Economies of scale Electric power distribution Electric utilities