A Global Model for Forecasting Political Instability

Examining onsets of political instability in countries worldwide from 1955 to 2003, we develop a model that distinguishes countries that experienced instability from those that remained stable with a two-year lead time and over 80% accuracy. Intriguingly, the model uses few variables and a simple specification. The model is accurate in forecasting the onsets of both violent civil wars and nonviolent democratic reversals, suggesting common factors in both types of change. Whereas regime type is typically measured using linear or binary indicators of democracy/autocracy derived from the 21-point Polity scale, the model uses a nonlinear five-category measure of regime type based on the Polity components. This new measure of regime type emerges as the most powerful predictor of instability onsets, leading us to conclude that political institutions, properly specified, and not economic conditions, demography, or geography, are the most important predictors of the onset of political instability.     

The Use of Race and Ethnicity in Medicine: Lessons from the African-American Heart Failure Trial

Race or ethnic identity, despite its imprecise categorization, is a useful means of identifying population differences in mechanisms of disease and treatment effects. Therefore, race and other arbitrary demographic and physiological variables have appropriately served as a helpful guide to clinical management and to clinical trial participation. The African-American Heart Failure Trial was carried out in African-Americans with heart failure because prior data had demonstrated a uniquely favorable effect in this subpopulation of the drug combination in BiDil. The remarkable effect of the drug in reducing mortality in this study has illuminated an important new mechanism of therapy for heart failure. Application of these findings need not be confined to the population studied, but the observation highlights the need for more precise ways to identify individual responsiveness to therapy.