Preface. Notation. Regression Models. Sampling. Time Series. Point Estimation. Statistical Accuracy and Hypothesis Testing. The Classical Linear Model: Estimation. Violations of the Ideal Conditions for OLS. Diagnostics Based on the O

This paper studies what happens when we move from a short regression to a long regression (or vice versa), when the long regression is shorter than the data-generation process. In the special case where the long regression equals the data-generation process, the least-squares estimators have...