The instrumental variable (IV) estimator in a cross-sectional or panel regression model is often taken to provide valid causal inference from contemporaneous correlations. In this exercise we point out that the IV estimator, like the OLS estimator, cannot be used effectively for causal inference...

The link between mental stress and cancer is still a belief, not a well established scientific fact. Scientists have relied largely on opinions of cancer stricken patients to establish a link between stress and cancer. Such opinion surveys tend to produce contradictory statistical inferences....

The existing measures of housing affordability are essentially short-run indicators that compare current income with property prices. Taking into consideration that a housing purchase is a long-horizon decision and the property price reflects the discounted present value of future mortgage...