Economic and Hypothetical Dictator Game Experiments: Incentive Effects at the Individual Level

The paper compares behavior in economic dictator game experiments played with actual money (amounts given by "dictator" subjects) with behavior in hypothetical dictator game experiments where subjects indicate what they would give, although no money is actually exchanged. The average amounts transferred in the two experiments are remarkably similar. Moreover, we uncover meaningful individual differences in real and hypothetical allocations and demonstrate the importance of two personality traits - agreeableness and extraversion - in reconciling them. We conclude that extraverts are "all talk;" agreeable subjects are "for real."Dictator Game, Incentives, Individual Differences, Personality

When Little Things Mean a Lot: On the Inefficiency of Item Pricing Laws

Item pricing laws (IPLs) require a price tag on every item sold by a retailer. We study IPLs and assess their efficiency by quantifying their costs and comparing them to previously documented benefits. On the cost side, we posit that IPLs should lead to higher prices because they increase the cost of pricing as well as the cost of price adjustment. We test this prediction using data collected from large supermarket chains in the Tri-State area of New York, New Jersey and Connecticut, which offer a unique setting because these states vary in their use of IPLs, but otherwise offer geographical proximity with each other and similar markets, supermarket chains, and socioeconomic environments. We find that IPL store prices are higher by about 20¢–25¢ or 8.0%–9.6% per item on average, in comparison to non-IPL stores. As a control, we use data from stores that are exempt from IPL requirements (because they use electronic shelf labels), and find that their prices fall between IPL and non-IPL store prices. To assess the efficiency of IPLs, we compare these costs to existing measures of the benefits of IPLs which are based on measurements of the frequency and the magnitude of pricing errors the IPLs are supposed to prevent. We find that the costs of IPLs are an order of magnitude higher than the upper bound of these estimate benefits.Item Pricing Law; Cost of Item Pricing Law; Cost of Price Adjustment; Menu Cost; Retail Pricing;

Emergence of System Optimum: A Fair and Altruistic Agent-based Route-choice Model

AbstractThe System Optimum, an optimal traffic assignment that minimizes the total travel costs on the road network is usually only referred to as a comparison to self-emerging user equilibrium. In this paper we investigate how different behavioral aspects of drivers can self-organize towards a system optimum that minimizes travel costs while providing benefits and preserving equity among drivers. We present a simple binary route-choice Agent-Based Model that provides a disaggregated view of driver behavior and a unique understanding of the potential of cognitive reinforcement models to effect a convergence to user equilibrium and a shift in driver behavior toward a system optimum without the need for an enforcing traffic policy such as tolls

Ancient technology and punctuated change: Detecting the emergence of the Edomite Kingdom in the Southern Levant.

While the punctuated equilibrium model has been employed in paleontological and archaeological research, it has rarely been applied for technological and social evolution in the Holocene. Using metallurgical technologies from the Wadi Arabah (Jordan/Israel) as a case study, we demonstrate a gradual technological development (13th-10th c. BCE) followed by a human agency-triggered punctuated "leap" (late-10th c. BCE) simultaneously across the entire region (an area of ~2000 km2). Here, we present an unparalleled, diachronic archaeometallurgical dataset focusing on elemental analysis of dozens of well-dated slag samples. Based on the results, we suggest punctuated equilibrium provides an innovative theoretical model for exploring ancient technological changes in relation to larger sociopolitical conditions-in the case at hand the emergence of biblical Edom-, exemplifying its potential for more general cross-cultural applications

Herding, Heterogeneity, and Momentum Trading of Institutional Investors Across Asset Classes

This paper examines herding, heterogeneity, and momentum trading of institutional investors in Israel across a broad variety of financial assets. While previous studies typically focus on stocks only, we examine herding patterns, heterogeneity, and momentum trading of institutional investors in five asset classes. We find that during the sample period (1/2002 – 12/2011) large investors tended to herd more than medium and small-size investors. In contrast, small investors used momentum trading patterns more than medium and large-size investors. Homogeneity was found among large investors, especially pension funds, and during the first half of the 2000s, when investors purchased corporate bonds at the expense of government bonds. This phenomenon ended upon the beginning of the subprime crisis and against the backdrop of the financial difficulties of the bond issuers. In those years, panicked investors withdrew funds from the most liquid institutions (study funds), while infusing funds to pension and provident funds due to legally binding arrangements. We attribute some of the heterogeneous trading of the institutional investors, to those factors

Designing a High-Lift Performance Wingsuit

Many current wingsuits are at their aerodynamic limit due to poor performance from the fabric that makes them up. We propose to evaluate the benefit of adding a rigid wing to the wingsuit, using rapid prototyping in a 3D printer and non-dimensional wind tunnel analysis

Chatting Makes Perfect -- Chat-based Image Retrieval

Chats emerge as an effective user-friendly approach for information retrieval, and are successfully employed in many domains, such as customer service, healthcare, and finance. However, existing image retrieval approaches typically address the case of a single query-to-image round, and the use of chats for image retrieval has been mostly overlooked. In this work, we introduce ChatIR: a chat-based image retrieval system that engages in a conversation with the user to elicit information, in addition to an initial query, in order to clarify the user's search intent. Motivated by the capabilities of today's foundation models, we leverage Large Language Models to generate follow-up questions to an initial image description. These questions form a dialog with the user in order to retrieve the desired image from a large corpus. In this study, we explore the capabilities of such a system tested on a large dataset and reveal that engaging in a dialog yields significant gains in image retrieval. We start by building an evaluation pipeline from an existing manually generated dataset and explore different modules and training strategies for ChatIR. Our comparison includes strong baselines derived from related applications trained with Reinforcement Learning. Our system is capable of retrieving the target image from a pool of 50K images with over 78% success rate after 5 dialogue rounds, compared to 75% when questions are asked by humans, and 64% for a single shot text-to-image retrieval. Extensive evaluations reveal the strong capabilities and examine the limitations of CharIR under different settings

Stability of Relativistic Matter with Magnetic Fields for Nuclear Charges up to the Critical Value

We give a proof of stability of relativistic matter with magnetic fields all the way up to the critical value of the nuclear charge $Z\alpha=2/\pi$.Comment: LaTeX2e, 12 page