Regression Artifacts

The term regression artifacts refers to pseudoeffects from a regression type of analysis. These incorrect causal estimates are due to biases from causes other than the cause of interest. Note that such artifacts are problems only when making causal inferences, not when merely predicting some future outcome. A famous regression artifact, for example, was that the first major evaluation of Head Start concluded that the summer program actually caused children to do worse in school. If this were merely a prediction, it would have been correct that having attended Head Start would predict poorer performance in school. These children did poorly in school because of their disadvantaged status, which Head Start could not completely compensate for. This correct prediction becomes an artifact only when someone ...