Preferences and Beliefs in a Sequential Social Dilemma: A Within-Subjects Analysis

Within-subject data from sequential social dilemma experiments reveal a correlation of first-and second-mover decisions for which two channels may be responsible, that our experiment allows to separate: i) a direct, preference-based channel that influences both first- and second-mover decisions; ii) an indirect channel, where second-mover decisions influence beliefs via a consensus effect, and the first-mover decision is a best response to these beliefs. We find strong evidence for the indirect channel: beliefs about second-mover cooperation are biased toward own second-mover behavior, and most subjects best respond to stated beliefs. But when first movers know the true probability of second-mover cooperation, subjects' own second moves still have predictive power regarding their first moves, suggesting that the direct channel also plays a role.experimental economics, consensus effect, social dilemmas

Cosmic ray spectral hardening due to dispersion in the source injection spectra

Recent cosmic ray (CR) experiments discovered that the CR spectra experience a remarkable hardening for rigidity above several hundred GV. We propose that this is caused by the superposition of the CR energy spectra of many sources that have a dispersion in the injection spectral indices. Adopting similar parameters as those of supernova remnants derived from the Fermi $\gamma$-ray observations, we can reproduce the observational CR spectra of different species well. This may be interpreted as evidence to support the supernova remnant origin of CRs below the knee. We further propose that the same mechanism may explain the "ankle" of the ultra high energy CR spectrum.Comment: 5 pages, 3 figures and 1 table. Updated with the diffusion propagation model, accepted by Phys. Rev.

Possible "dawn" and "dusk" roles of light pulses shifting the phase of a circadian rhythm

A new automatic photoelectric method used in recording the eclosion rate of flies is described. The phase responses of the circadian rhythm of eclosion in Drosophila pseudoobscura to light pulses, of 1000 lx intensity and durations varying between 30 min and 12 h, were studied. The rhythm responds selectively either to the "on" or to the "off" transition of light pulses offered during the subjective night. The light pulses shift phase with the off transition during the first half of the night (dusk effect) and shift phase with the "on" transition during the second half of the night (dawn effect). The present findings are briefly discussed in the context of the work of other authors in this field

Interference Leakage Neutralization in Two-Hop Wiretap Channels with Partial CSI

In this paper, we analyze the four-node relay wiretap channel, where the relay performs amplify-and-forward. There is no direct link between transmitter and receiver available. The transmitter has multiple antennas, which assist in securing the transmission over both phases. In case of full channel state information (CSI), the transmitter can apply information leakage neutralization in order to prevent the eavesdropper from obtaining any information about the signal sent. This gets more challenging, if the transmitter has only an outdated estimate of the channel from the relay to the eavesdropper. For this case, we optimize the worst case secrecy rate by choosing intelligently the beamforming vectors and the power allocation at the transmitter and the relay

Belief elicitation in experiments: is there a hedging problem?

Belief elicitation in economics experiments usually relies on paying subjects according to the accuracy of stated beliefs in addition to payments for other decisions. Such incentives, however, allow risk-averse subjects to hedge with their stated beliefs against adverse outcomes of other decisions in the experiment. This raises two questions: (i) can we trust the existing belief elicitation results, (ii) can we avoid potential hedging confounds? Our results instill confidence regarding both issues. We propose an experimental design that eliminates hedging opportunities, and use this to test for the empirical relevance of hedging effects in the lab. We find no evidence for hedging, comparing the standard hedging-prone belief elicitation treatment to a hedging-proof design in a sequential prisoners´ dilemma game. Our findings are strengthened by the absence of hedging even in an additional non-belief elicitation treatment using a financial investment frame, where hedging arguably would be most natural

Preferences and beliefs in a sequential social dilemma: A within-subjects analysis

In empirical analyses of games, preferences and beliefs are typically treated as independent. However, if beliefs and preferences interact, this may have implications for the interpretation of observed behavior. Our sequential social dilemma experiment allows us to separate different interaction channels. When subjects play both roles in such experiments, a positive correlation between first- and second-mover behavior is frequently reported. We find that the observed correlation primarily originates via an indirect channel, where second-mover decisions influence beliefs through a consensus effect, and the first-mover decision is a best response to these beliefs. Specifically, beliefs about second-mover cooperation are biased toward own second-mover behavior, and most subjects best respond to stated beliefs. However, we also find evidence for a direct, preference-based channel. When first movers know the true probability of second-mover cooperation, subjects' own second moves still have predictive power regarding their first moves

Blurring Borders: Innate Immunity with Adaptive Features

Adaptive immunity has often been considered the penultimate of immune capacities. That system is now being deconstructed to encompass less stringent rules that govern its initiation, actual effector activity, and ambivalent results. Expanding the repertoire of innate immunity found in all invertebrates has greatly facilitated the relaxation of convictions concerning what actually constitutes innate and adaptive immunity. Two animal models, incidentally not on the line of chordate evolution (C. elegans and Drosophila), have contributed enormously to defining homology. The characteristics of specificity and memory and whether the antigen is pathogenic or nonpathogenic reveal considerable information on homology, thus deconstructing the more fundamentalist view. Senescence, cancer, and immunosuppression often associated with mammals that possess both innate and adaptive immunity also exist in invertebrates that only possess innate immunity. Strict definitions become blurred casting skepticism on the utility of creating rigid definitions of what innate and adaptive immunity are without considering overlaps

Preferences and beliefs in a sequential social dilemma: a within-subjects analysis

Within-subject data from sequential social dilemma experiments reveal a correlation of first-and second-mover decisions for which two channels may be responsible, that our experiment allows to separate: i) a direct, preference-based channel that influences both first- and second-mover decisions; ii) an indirect channel, where second-mover decisions influence beliefs via a consensus effect, and the first-mover decision is a best response to these beliefs. We find strong evidence for the indirect channel: beliefs about second-mover cooperation are biased toward own second-mover behavior, and most subjects best respond to stated beliefs. But when first movers know the true probability of second-mover cooperation, subjects' own second moves still have predictive power regarding their first moves, suggesting that the direct channel also plays a role