2,549 research outputs found
The coordination value of monetary exchange: Experimental evidence
Under what conditions can cooperation be sustained in a network of strangers? Here we study the role of institutions and uncover a new behavioral foundation for the use of monetary systems. In an experiment, anonymous subjects could cooperate or defect in bilateral random encounters. This sequence of encounters was indefinite; hence multiple equilibria were possible, including full intertemporal cooperation supported by a social norm based on community punishment of defectors. We report that such social norm did not emerge. Instead, the availability of intrinsically worthless tokens favored the coordination on intertemporal cooperation in ways that networks of strangers were unable to achieve through social norms.
A novel approach in the WIMP quest: Cross-Correlation of Gamma-Ray Anisotropies and Cosmic Shear
Both cosmic shear and cosmological gamma-ray emission stem from the presence
of Dark Matter (DM) in the Universe: DM structures are responsible for the
bending of light in the weak lensing regime and those same objects can emit
gamma-rays, either because they host astrophysical sources (active galactic
nuclei or star-forming galaxies) or directly by DM annihilations (or decays,
depending on the properties of the DM particle). Such gamma-rays should
therefore exhibit strong correlation with the cosmic shear signal. In this
Letter, we compute the cross-correlation angular power spectrum of cosmic shear
and gamma-rays produced by the annihilation/decay of Weakly Interacting Massive
Particle (WIMP) DM, as well as from astrophysical sources. We show that this
observable provides novel information on the composition of the Extra-galactic
Gamma-ray Background (EGB), since the amplitude and shape of the
cross-correlation signal strongly depends on which class of source is
responsible for the gamma-ray emission. If the DM contribution to the EGB is
significant (at least in a definite energy range), although compatible with
current observational bounds, its strong correlation with the cosmic shear
makes such signal potentially detectable by combining Fermi-LAT data with
forthcoming galaxy surveys, like Dark Energy Survey and Euclid. At the same
time, the same signal would demonstrate that the weak lensing observables are
indeed due to particle DM matter and not to possible modifications of General
Relativity.Comment: 6 pages, 12 figures. v2: Matches version published in ApJ Lett. Text
reorganized, appendix removed (part of the discussion is now in the main
text), no major change
Communication, commitment, and deception in social dilemmas: experimental evidence
Social norms of cooperation are studied under several forms of communication. In an experiment, strangers could make public statements before playing a prisoner’s dilemma. The interaction was repeated indefinitely, which generated multiple equilibria. Communication could be used as a tool to either signal intentions to coordinate on Pareto-superior outcomes, to deceive others, or to credibly commit to actions. Some forms of communication did not promote the incidence of efficient Nash play, and sometimes reduced it. Surprisingly, cooperation suffered when subjects could publicly commit to actions.
A follow-up study of the students of the X secretarial school
Thesis (Ed.M.)--Boston University, 1947. This item was digitized by the Internet Archive
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