The perils of adding up: a cautionary tale about modeling and regression analysis.
To turn incomplete or imperfectly reliable information into estimates useful for policy, some modeling is often necessary or helpful. It does not follow that every statistical relation constitutes a model. There has to be an underlying theory, and the numerical estimates must respect any definitional or accounting identities that constrain the results. Ad hoc relations that do not meet these criteria can lead to uninterpretable or meaningless values, especially when different partial values, separately estimated, are added together. The imputed values of "responsiveness" in the WHO World Health Report 2000 illustrate this danger.
Musgrove
Philip
P
Disease Control Priorities Project, Fogarty International Center, National Institutes of Health, Bethesda, MD 20892, USA. musgrovp@mail.nih.gov
D014943:Global Health; D015233:Models, Statistical; D012044:Regression Analysis; D014944:World Health Organization