The Role of Feedback in Dynamic Crowdsourcing Contests: A Structural Empirical Analysis

In this paper, we empirically examine the impact of performance feedback on the outcome of crowdsourcing contests. We develop a dynamic structural model to capture the economic processes that drive contest participants’ behavior and estimate the model using a detailed data set about real online logo design contests. Our rich model captures key features of the crowdsourcing context, including a large participant pool; entries by new participants throughout the contest; exploitation (revision of previous submissions) and exploration (radically novel submissions) behaviors by contest incumbents; and the participants’ strategic choice among these entry, exploration, and exploitation decisions in a dynamic game. Using counterfactual simulations, we compare the outcome of crowdsourcing contests under alternative feedback disclosure policies and award levels. Our simulation results suggest that, despite its prevalence on many platforms, the full feedback policy (providing feedback throughout the contest) may not be optimal. The late feedback policy (providing feedback only in the second half of the contest) leads to a better overall contest outcome. This paper was accepted by Gabriel Weintraub, revenue management and market analytics department.

The hidden links between animal weapons, fighting style and their expression on contest resolution

SUMMARYIn many species that fight over resources, individuals use specialized structures to overpower their rivals (i.e. weapons). Despite their similar roles for contest settlement (i.e. affecting the winning chances), weapons are highly diverse morphological structures across species. However, the comprehension on how this diversity evolved is still open for debate.Unfortunately, most studies on how weapons are used during contests focus on size asymmetries between winners and losers. Although such information is important to understand, it does not provide much information regarding the mechanisms promoting weapon diversification. In addition, in many situations, the effect of weapon size on contest resolution may be confounded with the effect of body size due to allometric correlations.One way to decompose the relative importance of weapon and body size on contest outcome is to focus on the functional role of weapons. That is, investigate the function of the weapon during contests, and how size should affect its function.We propose two hypotheses that explicitly associate how weapon function may determine the relative importance of weapon and body size in affecting rivals during contests. One based on the internal morphology of the weapon – whether muscles are within the weapon or not – and the other based on fighting style – whether the weapon is used to injure the rival or not.To test our hypotheses, we developed a meta-analysis spanning 31 genera across the animal kingdom.We found that internal morphology and fighting style are important to determine the relative importance of weapon and body size on contest resolution. Weapons that do not have muscles within them (e.g., horns) affect more the chance of winning than weapons that have muscles within them (e.g., claws). Similarly, weapons used to throw/push rivals away (e.g., oversized mandibles) affect more the chance of winning than those used to make the rival flee (e.g., jaws).Overall, we have shown that weapon usage (i.e. weapon function) may affect weapon evolution in predictable ways: weapons without muscles and using for pushing may be selected for size, while muscled weapons used for injuring may be selected for strength.

The role of personality, cognition, and affective state in same-sex contests in the red junglefowl

Intra-species contests are common in the animal kingdom and can have fitness consequences. Most research on what predicts contest outcome focuses on morphology, although differences in personality and cognition may also be involved. Supporting this, more proactive individuals often have dominant status, although the causality of this relationship is rarely investigated. Contest initiators often win; thus, individuals that are more proactive in their personality (e.g., more aggressive, risk-taking) or cognition (e.g., more optimistic, impulsive) may initiate contests more often. To investigate this, we assayed the behavior and cognition of sexually mature male and female red junglefowl (Gallus gallus), a species in which both sexes contest over social status, before staging intra-sexual contests. We confirm that contest initiators were more likely to win. In males, individuals that behaved more boldly in a novel arena test were more likely to initiate and win contests. Female initiators tended to be less active in novel object test, more aggressive in a restrained opponent test, and respond less optimistically in a cognitive judgement bias test, whereas the main predictor of whether a female would win a contest was whether she initiated it. These results suggest that behaviors attributed to proactive and reactive personalities, and—at least for female red junglefowl—optimism, can affect contest initiation and outcome. Therefore, within species, and depending on sex, different aspects of behavior and cognition may independently affect contest initiation and outcome. The generality of these findings, and their fitness consequences, requires further investigation. Significance statement In red junglefowl, we explored how behavior previously shown to describe personality, cognition, and affective state affected initiation and outcome of intra-sexual contests, by staging contests between sexually mature individuals previously assayed in behavioral and cognitive tests. In both sexes, contest initiators usually won. Bolder males were more likely to initiate and win contests. Female contests initiators were less active, more aggressive, and less optimistic. Our results suggest that personality and cognition could affect the initiation and outcome of contests and that how this occurs may differ between sexes.

Game of webs: species and web structure influence contest outcome in black widow spiders

Population-level trait variation within species plays an often-overlooked role in interspecific interactions. In this study, we compared among-individual variation in web phenotype and foraging behavior between native black widows (Latrodectus hesperus) and invasive brown widows (Latrodectus geometricus). We staged repeated contests whereby native widows defended their webs against intruders of both species to 1) investigate how trait variation mediates web contest outcome among native widows and 2) see whether widow behavior differs in response to an invasive spider. In only one trait, the average number of foraging lines, did black widows differ from brown widows. Black widow residents that built more structural lines were more likely to successfully defend their webs from conspecific intruders (i.e., be the sole spider remaining on the web postinteraction). This association between web structure and contest outcome did not exist in trials between black widows and invasive brown widows; however, in interspecific interactions, these same residents were more likely to have intruders remain on the web rather than drive them away. Surprisingly, brown widows did not usurp black widows. Brown widows were never observed signaling, yet black widow residents signaled equally to intruders of both species. Our results suggest that among-individual variation among native species can influence the response toward invasive competitors and outcome of these interactions.