Unobservable Selection and Coefficient Stability

Implementation of: "Unobservable selection and coefficient stability: Theory and evidence.", Oster E, JBES 37.2 (2019)

The function implements the method of (*) for evaluating robustness to omitted variable bias.
Specifically, it implements Proposition 2, Corollary 1 and Proposition 3. The implementation relies upon Matlab's fitlm(). Examples included for both computing the (a) bias-adjusted treatment
effect and (b) the delta value (bound) to match a given treatment effect, for the unrestricted estimator under additional (unrelated) controls. The complete documentation is within the function oster.mat.

(*) Oster, Emily. "Unobservable selection and coefficient stability: Theory and evidence." Journal of Business & Economic Statistics 37.2 (2019): 187-204.