In the classical regression model with fixed regressors the statistic S2, i.e. the sum of squared residuals (SSR) divided by the number of degrees of freedom is an unbiased estimator of the variance of the disturbances. If the model is dynamic and contains lagged-dependent explanatory variables,...

Regression of a trendless random walk on time produces R-squared values around .44 regardless of sample length. The residuals from the regression exhibit only about 14 percent as much variation as the original series even though the underlying process has no functional dependence on time. The...

Volatility tests are an alternative to regression tests for evaluating the joint null hypothesis of market efficiency and risk neutrality. Acomparison of the power of the two kinds of tests depends on what the alternative hypothesis is taken to be. By considering tests based on conditional...