Feeling cold is contagious

Seeing someone plunge into an ice-cold bath induces feelings of cold. However, it was recently demonstrated that viewing another's skin temperature change also induces a small congruent temperature change in the observer. This synchronization suggests top-down influences on peripheral temperature regulation mechanisms and lends supports to somatic-simulation theories of inter-subjectivity

Is Crime Contagious?

We test the hypothesis that criminal behavior is “contagious” – or susceptible to what economists term “endogenous effects” – by examining the extent to which lower local-area crime rates decrease arrest rates among individuals. Using data from the Moving to Opportunity (MTO) randomized housing-mobility experiment, in operation since 1994 in five U.S. cities, we exploit the fact that the effect of treatment group assignment yields different types of neighborhood changes across the five demonstration sites and use treatment-site interactions to instrument for measures of post-randomization neighborhood crime rates as well as neighborhood poverty or racial segregation in analysis of individual arrest outcomes. We find no evidence that violence is contagious; neighborhood racial segregation appears to be the most important explanation for across-neighborhood variation in arrests for violent crimes. Our only evidence for contagion comes with less serious crimes. Some estimates suggest an effect for males, but these results are imprecise. We also find evidence that young males are more likely to engage in property crimes when violent crimes are relatively more prevalent within the community. These findings are consistent with a “resource swamping” model in which increases in the prevalence of more serious crimes dilutes the police resources available for deterring less serious crimes.endogenous effects, social multiplier, arrests, social experiment

Partial information about contagion risk, self-exciting processes and portfolio optimization : [Version 18 April 2013]

This paper compares two classes of models that allow for additional channels of correlation between asset returns: regime switching models with jumps and models with contagious jumps. Both classes of models involve a hidden Markov chain that captures good and bad economic states. The distinctive feature of a model with contagious jumps is that large negative returns and unobservable transitions of the economy into a bad state can occur simultaneously. We show that in this framework the filtered loss intensities have dynamics similar to self-exciting processes. Besides, we study the impact of unobservable contagious jumps on optimal portfolio strategies and filtering

Is Crime Contagious?

endogenous effects, social multiplier, arrests, social experiment

Contagious Currency Crises

This paper is concerned with the fact that the incidence of speculative attacks tends to be temporally correlated; that is, currency crises appear to pass contagiously from one country to another. The paper provides a survey of the theoretical literature, and analyzes the contagious nature of currency crises empirically. Using thirty years of panel data from twenty industrialized countries, we find evidence of contagion. Contagion appears to spread more easily to countries which are closely tied by international trade linkages than to countries in similar macroeconomic circumstances.

Are bank runs contagious?

History shows that banks are subject to runs and panics. Researchers disagree, however, about whether runs are contagious: that is, do problems at insolvent banks spread to solvent ones? If runs are contagious, what, if anything, can be done to stop the spread, and what are the implications for deposit insurance and banking regulations? In this article, Ted Temzelides reviews the basic theory and presents some recent evidence on contagious bank runsBank failures

Dogs catch human yawns

This study is the first to demonstrate that human yawns are possibly contagious to domestic dogs (Canis familiaris). Twenty-nine dogs observed a human yawning or making control mouth movements. Twenty-one dogs yawned when they observed a human yawning, but control mouth movements did not elicit yawning from any of them. The presence of contagious yawning in dogs suggests that this phenomenon is not specific to primate species and may indicate that dogs possess the capacity for a rudimentary form of empathy. Since yawning is known to modulate the levels of arousal, yawn contagion may help coordinate dog–human interaction and communication. Understanding the mechanism as well as the function of contagious yawning between humans and dogs requires more detailed investigation

Core Lexicon and Contagious Words

We present the new empirical parameter $f_c$, the most probable usage frequency of a word in a language, computed via the distribution of documents over frequency $x$ of the word. This parameter allows for filtering the core lexicon of a language from the content words, which tend to be extremely frequent in some texts written in specific genres or by certain authors. Distributions of documents over frequencies for such words display long tails as $x>f_c$ representing a bunch of documents in which such words are used in abundance. Collections of such documents exhibit a percolation like phase transition as the coarse grain of frequency $\Delta f$ (flattening out the strongly irregular frequency data series) approaches the critical value $f_c$.Comment: RevTex, 4 pages, 2 figure