Supersymmetric hadronic bound state detection at e+e−e^+e^- colliders

We review the possibility of formation for a bound state made out of a stop quark and its antiparticle. The detection of a signal from its decay has been investigated for the case of a $e^+e^-$ collider.Comment: 13 pages, 11 figure

Social Image Concerns and Pro-Social Behavior

Using longitudinal data on the entire population of blood donors in an Italian town, we examine how donors respond to an award scheme which rewards them with “medals” when they reach certain donation quotas. Our results indicate that donors significantly increase the frequency of their donations immediately before reaching the thresholds for which the rewards are given, but only if the prizes are publicly announced in the local newspaper and awarded in a public ceremony. The results are robust to several specifications, sample definitions, and controls for observable and unobservable heterogeneity. Our findings are consistent with social image concerns being a primary motivator of pro-social behavior, and indicate that symbolic prizes are most effective as motivators when they are awarded publicly. Because we do not detect a reduction in donation frequency after the quotas are reached, this incentive based on social prestige leads to a net increase in the frequency of donations.incentives, awards, public good provision, pro-social behavior, public health, social prestige

Motivating Altruism: A Field Study

This paper analyzes the effects of a legislative provision that grants a one-day paid leave of absence to blood donors who are employees in Italy. The analysis is based on a unique dataset with the complete donation histories of the blood donors in an Italian town. The cross-sectional variation in job market status and type of employers, and job switching over time by a subset of donors, are the sources of variation we employ to study whether donors are responsive to the paid-day-off incentive in the choice of their donation days, and in the frequency of their donations. Our results indicate that economic considerations do affect blood donation decisions, for donors donate in days of the week that, given the day-off benefit, maximize their material returns in terms of consecutive days off work. We also find evidence, however, consistent with heterogeneous motivations in different donors, since a subset of donors systematically do not take advantage of the material reward. Finally, we find that the day-off privilege leads donors who are employees to make, on average, one extra donation per year. We discuss the implications of our findings for policies aimed at increasing the supply of blood, and more generally for incentivizing pro-social behavior.incentives, altruism, public good provision, pro-social behavior, public health

Learning sound representations using trainable COPE feature extractors

Sound analysis research has mainly been focused on speech and music processing. The deployed methodologies are not suitable for analysis of sounds with varying background noise, in many cases with very low signal-to-noise ratio (SNR). In this paper, we present a method for the detection of patterns of interest in audio signals. We propose novel trainable feature extractors, which we call COPE (Combination of Peaks of Energy). The structure of a COPE feature extractor is determined using a single prototype sound pattern in an automatic configuration process, which is a type of representation learning. We construct a set of COPE feature extractors, configured on a number of training patterns. Then we take their responses to build feature vectors that we use in combination with a classifier to detect and classify patterns of interest in audio signals. We carried out experiments on four public data sets: MIVIA audio events, MIVIA road events, ESC-10 and TU Dortmund data sets. The results that we achieved (recognition rate equal to 91.71% on the MIVIA audio events, 94% on the MIVIA road events, 81.25% on the ESC-10 and 94.27% on the TU Dortmund) demonstrate the effectiveness of the proposed method and are higher than the ones obtained by other existing approaches. The COPE feature extractors have high robustness to variations of SNR. Real-time performance is achieved even when the value of a large number of features is computed.Comment: Accepted for publication in Pattern Recognitio

WILL THERE BE BLOOD? INCENTIVES AND SUBSTITUTION EFFECTS IN PRO-SOCIAL BEHAVIOR*

We present evidence from observational data on nearly 14,000 American Red Cross blood drives and from a randomized natural field experiment showing that economic incentives have a positive effect on blood donations without increasing the fraction of donors who come to a drive but are ineligible to donate. We also show that the effect of incentives on donations increases with the incentive's economic value. However, we further show that a substantial proportion of the increase in donations due to incentives may be explained by donors leaving neighboring drives without incentives to attend the drive with incentives, and the likelihood of this substitution is higher the higher the monetary value of the incentive offered. We conclude that extrinsic incentives stimulate pro-social behavior, but, unless substitution effects are also considered, the effect of incentives may be overesti mated.

Rewarding Altruism? A Natural Field Experiment

We present evidence from a natural field experiment involving nearly 100,000 individuals on the effects of offering economic incentives for blood donations. Subjects who were offered economic rewards to donate blood were more likely to donate, and more so the higher the value of the rewards. They were also more likely to attract others to donate, spatially alter the location of their donations towards the drives offering rewards, and modify their temporal donation schedule leading to a short-term reduction in donations immediately after the reward offer was removed. Although offering economic incentives, combining all of these effects, positively and significantly increased donations, ignoring individuals who took additional actions beyond donating to get others to donate would have led to an under-estimate of the total effect, whereas ignoring the spatial effect would have led to an over-estimate of the total effect. We also find that individuals who received a reward by surprise were less likely to donate after the intervention than subjects who received no reward, suggesting that for some individuals a surprise reward adversely affected their intrinsic motivations. We discuss the implications of these findings for understanding pro-social behavior.

Will There Be Blood? Incentives and Substitution Effects in Pro-social Behavior

We examine how economic incentives affect pro-social behavior through the analysis of a unique dataset with information on more than 14,000 American Red Cross blood drives. Our findings are consistent with blood donors responding to incentives in a "standard" way; offering donors economic incentives significantly increases turnout and blood units collected, and more so the greater the incentive's monetary value. In addition, there is no disproportionate increase in donors who come to a drive but are ineligible to donate when incentives are offered. Further evidence from a small-scale field experiment corroborates these findings and confirms that donors are motivated by the economic value of the items offered. We also find that a substantial fraction of the increase in donations due to incentives may be explained by donors substituting away from neighboring drives toward drives where rewards are offered, and the likelihood of this substitution is higher the higher the monetary value of the incentive offered and if neighboring drives do not offer incentives. Thus, extrinsic incentives motivate pro-social behavior, but unless substitution effects are also considered, the effect of incentives may be overestimated.incentives, altruism, public good provision, pro-social behavior, public health