Direct and Indirect Causal Effects via Potential Outcomes*

Abstract. The use of the concept of ‘direct’ versus ‘indirect’ causal effects is common, not only in statistics but also in many areas of social and economic sciences. The related terms of ‘biomarkers’ and ‘surrogates’ are common in pharmacological and biomedical sciences. Sometimes this concept is represented by graphical displays of various kinds. The view here is that there is a great deal of imprecise discussion surrounding this topic and, moreover, that the most straightforward way to clarify the situation is by using potential outcomes to define causal effects. In particular, I suggest that the use of principal stratification is key to understanding the meaning of direct and indirect causal effects. A current study of anthrax vaccine will be used to illustrate ideas.     

Trade-Offs Between Formal Home Health Care and Informal Family CareGiving

Using 1994 National Long Term Care Survey data, we estimated logistic regressions of formal and informal home health care use and hours. Home health care use and intensity were differentially impacted by chronic conditions, are higher for Medicaid enrollees and rural or small town residents, but lower for HMO enrollees. Decreases in the probability of home health care use increased informal instrumental activities of daily living (IADL) support four hours and decreased informal activities of daily living (ADL) support eight hours weekly. IADL caregiving substituted for formal care, but ADL caregiving declined with reductions in formal care. Public policy reducing formal home health care access may reduce informal ADL caregiving and increase informal IADL caregiving, producing net declines in support.     

Learning how to learn: the key to CQI

All CQI/TQM efforts share a common purpose: to learn something that can correct past mistakes and/or to create better futures. Because learning is a dynamic circular process, the information about a problem or an opportunity will be limited unless four perceptions of the truth--each valid, and each incomplete--are accepted. These four types of learning styles or ways of perceiving are: abstract conceptualizers, active experimenters, concrete experiencers, and reflective observers. Unless all the stages of the learning process have been fully completed, unless all the strokes work in harmony, we cannot be confident that a CQI effort has added its full value. A CQI team's interpersonal process, the tools by which individually limited truths are forged into a consensual holistic truth, must ensure that the group's effort goes "around in circles."     

Advisers and the Fiduciary Duty Debate

This work concerns itself with the debate taking place in the United States about the duty of care financial advisers owe investors. On one side it is argued that advisers need only concern themselves with recommendations which meet certain suitability standards. On the other side, there are those who argue the suitability standard is not strong enough to adequately protect investor interests. Instead of ensuring investment recommendations are merely suitable, financial advisers owe their investors a fiduciary duty to “act in the best interest of the customer without regard to the financial or other interests … of the investment adviser providing the advice.” (SEC, 2011). In applying a properly understood conception of what fiduciary means I argue that regulations should not be harmonized but that fiduciary duty should apply to all who provide personalized investment advice to retail customers. I will further argue that even if the regulations are harmonized as proposed, because of exemptions for broker‐dealers as envisioned in the proposal, and which currently apply to Registered Investment Advisers, the efficacy of fiduciary duty is diluted to the point of rendering its current application, much less its potential uniform imposition, irrelevant.     

Shyness,Preference for Solitude,and Adolescent Internalizing: The Roles of Maternal,Paternal, and Best‐Friend Support

The researchers examined differential outcomes related to two distinct motivations for withdrawal (preference for solitude and shyness) as well as the possibility that support from important others (mothers, fathers, and best friends) attenuate any such links. Adolescents (159 males, 171 females) reported on their motivations to withdraw, internalizing symptoms, and relationship quality in eighth grade, as well as their anxiety and depression in ninth grade. Using structural equation modeling, the authors found that maternal support weakened the association between shyness and internalizing problems; friend support weakened the association between preference for solitude and depression; and friend support strengthened the association between shyness and depression. Results suggest that shy adolescents may not derive the same benefits from supportive friendships as their typical peers.