Least Squares Regression Statistical Inference

Overview


When running an OLS regression, it is often useful to get an estimate of the likelihood that the results of the regression are close to the true values. In particular, it is often useful to determine if a given coefficient is likely to be different than zero.

This type of analysis utilizes the tools of statistical inference and Hypothesis Testing to provide confidence intervals around the calculated results.

Unfortunately, it is not possible to run a hypothesis test without making additional assumptions about the distibution that created the dataset. The most common assumption is that the model errors {% \epsilon %} are normally distributed (see Normality assumption)

Statistics


The primary hypothesis tests run on an OLS regression are based on the following test statistics

  • T-Statistic and P Value - tests whether a single coefficient is non-zero
  • F-Test - tests whether at least one coefficient is non-zero

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