Home Curriculum Vitae Research Teaching
Xiaofei (Sophia) Pan (潘晓菲）
Ph.D. Candidate, Interdisciplinary Center for Economic Science,
Phone: 703-993-4845 (office)
Email: xpan2@gmu.edu
Competition for Trophies Triggers Male Generosity (
PloSOne 2011, with Daniel Houser)Background: Cooperation is indispensable in human societies, and much progress has been made towards understanding human pro-social decisions. Formal incentives, such as punishment, are suggested as potential effective approaches despite the fact that punishment can crowd out intrinsic motives for cooperation and detrimentally impact efficiency. At the same time, evolutionary biologists have long recognized that cooperation, especially food sharing, is typically efficiently organized in groups living on wild foods, even absent formal economic incentives. Despite its evident importance, the source of this voluntary compliance remains largely uninformed. Drawing on costly signaling theory, and in light of the widely established competitive nature of males, we hypothesize that unique and displayable rewards (trophies) out of competition may trigger male generosity in competitive social environments.
Principle Findings: Here, we use a controlled laboratory experiment to show that cooperation is sustained in a generosity competition with trophy rewards, but breaks down in the same environment with equally valuable but non-unique and non-displayable rewards. Further, we find that males’ competition for trophies is the driving force behind treatment differences. In contrast, it appears that female competitiveness is not modulated by trophy rewards.
Significance: Our results suggest new approaches to promoting cooperation in human groups that, unlike punishment mechanisms, do not sacrifice efficiency. This could have important implications in any domain where voluntary compliance matters --- including relations between spouses, employers and employees, market transactions, and conformity to legal standards.
Mating Strategies and Gender Differences in Prosociality: Theory and Evidence (CESifo Economic Studies, 2011, with Daniel Houser)
This article examines gender differences in prosociality using theories from evolutionary psychology and empirical evidence from experimental economics. Although there has been extensive research in both fields, there remains a large disconnect between the source of gender differences in pro-sociality and experimental research aimed at informing cooperation and generosity. Thus, the main contribution of our article is to bridge this gap by arguing that differences in male and female motives for prosociality stem, at least in part, from gender differences in mating strategies. In particular, we discuss gender differences in: (i) signaling behaviors; (ii) conformance to social norms; and (iii) approaches toward resolving intra- and inter-group dilemmas. This article may be a useful resource for those hoping to gain a better understanding of the foundations of gender differences in prosociality; likewise, it draws useful attention to empirical research aimed at promoting charitable giving and enhancing resource allocation efficiency.
Social Approval, Competition and Cooperation
with Daniel Houser (Job Market Paper, under review)Holländer (1990) argued that when non-monetary social approval from peers is sufficiently valuable, it works to promote cooperation. Holländer, however, did not define the characteristics of environments in which high valued approval is likely to occur. This paper provides evidence from a laboratory experiment indicating that people under competition value approval highly, but only when winners earn visible rewards through approval. The evidence implies that approval’s value is tied to signaling motives. Our findings point to new institutions that rely on reward, rather than punishment, to efficiently promote generosity in groups.
The causal effect of market participation on trust: An experimental investigation using randomized control, with Omar Al-Ubaydli, Dan Houser, John Nye and Maria Pia Paganelli (under review)
In randomized control laboratory experiments, we find that those primed to think about markets exhibit more trusting behavior. We randomly and unconsciously prime experimental participants to think about market and trade. We then ask them to play a trust game involving an anonymous stranger. We compare the behavior of these individuals with that of group who are not primed to think about anything in particular. Priming for market participating affects positively the beliefs about the trustworthiness of anonymous strangers, increasing trust.
Experiment on the Demand for Encompassment, with Daniel Klein, Daniel Houser and Gonzalo Schwarz (under review)
The idea of political community is appealing on a gut-level. Hayek suggested that certain genes and instincts still dispose us toward the ethos and mentality of the hunter-gatherer band, and that modern forms of political collectivism have, in part, been atavistic reassertions of such tendencies. Picking up on Hayek, Klein (2005) has suggested a combination of yearnings: 1) a yearning for coordinated sentiment (like Smithian sympathy); and 2) a yearning that the sentiment encompass the whole group. This paper reports on an experiment designed to explore the demand for encompassment by having subjects sing together. In each trial, one person in the room was designated not to sing unless every one of the others in the room had made a payment sufficient so as to have that person sing. Subjects chose to sacrifice money to achieve encompassment 47.4 percent of the time, with 59.6 percent of the subjects doing so in at least one trial. An exit questionnaire showed that subjects’ chief reason for making such a sacrifice was a belief that the singing would be more enjoyable if it encompassed the whole group, and reported enjoyment is significantly higher with encompassment. We discuss the experiment as a parable for a penchant toward political collectivism.
Promoting Trust with Outgroups (with Daniel Houser)
Abstract: In-group favoritism is well established and its psychological foundations have been extensively studied. Here we ask hether the process by which a group forms might impact in-group bias. We use two variants of a minimal group paradigm to create groups in the lab. Both paradigms involve solving puzzles, but one of the puzzles is designed to require much more cooperation to solve. Following the puzzle task participants play trust-games with in-group and out-group members. We find that members of groups that formed using a task that required high-cooperation are also significantly more trusting of out-group members. There is no difference in the propensity to trust the in-group. Consequently, forming groups using a relatively more cooperative task mitigates in-group bias and significantly increases economic efficiency.
Punishment and forgiveness among groups (with Daniel Houser)
A substantial literature suggests that maintaining trust relationships among different social or political groups is critical for economic growth and development. Because occasional violations of trust will occur, also critical is forgiveness. Here we use laboratory experiments to study trust and forgiveness among different groups in an environment with uncertainty. We ask how “betrayal” by an in- or out- group member impacts future willingness to trust a new in- or out-group member. We also investigate how these effects vary with the presence of punishment opportunities.