Instrumental Variables
Instrumental Variables is a scholarly work, published in 2006 in ''Epidemiology''. The main subjects of the publication include variable, mathematics, econometrics, medicine, causal inference, dependent and independent variables, sample size determination, estimator, confounding, omitted-variable bias, health economics, regularization, statistics, and instrumental variables estimation. The authors conclude that instrumental variables can be useful in case of moderate confounding but are less useful when strong confounding exists, because strong instruments cannot be found and assumptions will be easily violated.