Physicians' treatment decisions determine the level of health care spending to a large extent. The analysis of physician agency describes how doctors trade off their own and their patients' benefits, with a third party (such as the collective of insured individuals or the taxpayers) bearing the...

Individuals’ socioeconomic status (SES) is positively correlated with their health status. While the existence of this gradient may be uncontroversial, the same cannot be said about its explanation. In this paper, we extend the approach of testing for the absence of causal channels developed...