achieving the millennium development goals has proven to be a real challenge. providing evidence on cost-effective interventions did not prove to be sufficient to secure the trust of national authorities, health care providers and patients. introducing change in a health system requires a good understanding of the relationships between the actors of the system. social network analysis can provi...

Political units often spatially depend in their political choices on other units. This is no less so in dyadic settings where, as in much of international relations research, the focus of the analysis is the pair or dyad of two political units. Yet, with few exceptions social scientists have analyzed contagion only in monadic datasets, consisting of individual political units. This article expl...

This paper presents an empirical analysis of volatility and contagion across 19 emerging and developed stock markets in the 1990s. First, using an efficient estimate of unconditional stock return volatility we show that contemporaneous return and volatility correlation across stock markets have increased substantially in the 1990s. Second, using simple rolling regressions and goodness of fit me...

The automatic contagion of emotion is considered crucial in interpersonal communication. In face-to-face interactions, people could be both the receiver and sender of emotional content. Thus, contagion may have bidirectional influences on the emotional states of individuals. However, many studies have mainly dealt with unidirectional contagion, such that the expression of pain in a target entai...

The key role of emotions in decision-making process of human beings has been highlighted recently. Our research focuses on fear-related emotions and their positive impact on the survival capabilities of human beings in case of crisis situations. In this paper, we proposed a new model of emotional contagion based on some main findings in social psychology. This model was formalized mathematicall...

This longitudinal study examined peer contagion of depressive symptoms over an 18-month interval within a sample of 100 11th-grade adolescents. Three types of peer contagion moderators were examined, including characteristics of adolescents (social anxiety, global self-worth), friends (level of friends' peer-perceived popularity), and the relationship between them (friendship quality). Measures...

Models of contagion arise broadly in both the biological and the social sciences, with applications ranging from the transmission of infectious diseases to the spread of cultural fads. In this Letter, we introduce a general model of contagion which, by explicitly incorporating memory of past exposures to, for example, an infectious agent, rumor, or new product, includes the main features of exi...