1,721,010 research outputs found
Competing Conventions with Costly Information Acquisition
Full text linkWe consider an evolutionary model of social coordination in a 2 × 2 game where two groups of players prefer to coordinate on different actions. Players can pay a cost to learn their opponent’s group: if they pay it, they can condition their actions concerning the groups. We assess the stability of outcomes in the long run using stochastic stability analysis. We find that three elements matter for the equilibrium selection: the group size, the strength of preferences, and the information’s cost. If the cost is too high, players never learn the group of their opponents in the long run. If one group is stronger in preferences for its favorite action than the other, or its size is sufficiently large compared to the other group, every player plays that group’s favorite action. If both groups are strong enough in preferences, or if none of the groups’ sizes is large enough, players play their favorite actions and miscoordinate in inter-group interactions. Lower levels of the cost favor coordination. Indeed, when the cost is low, in inside-group interactions, players always coordinate on their favorite action, while in inter-group interactions, they coordinate on the favorite action of the group that is stronger in preferences or large enough
Four essays on social conventions
No full textIn this thesis, I analyze how and why social conventions emerge across distinct contexts and their impact on different economic environments. In the first and fourth chapters, I employ evolutionary game theory techniques to study the formation of social conventions in two strategic situations: a coordination game and a conflict game. In the second chapter, I use a signaling game to study the relevance of homophily in guiding the formation of social groups among employees and the consequent impact on labor market outcomes. In the third chapter, I conducted two field experiments to assess how people react to different shares of the population doing an activity, which is crucial in understanding the emergence of social conventions
Masks, cameras and social pressure
No full textIn this paper, we report the results of two experiments that randomise the share of individuals who are taking an action in subjects’ immediate environment. Despite the differences between our two settings (face masks and online camera use), we uncover some empirical results that are common to both. First, we find that the share of individuals taking the relevant action is increasing in the share of others who take the action (although the relationship need not be linear). Second, and despite this, we find that many individuals nonetheless defy social pressure. Our results point both to the importance of social pressure as well as its very real limits in our settings
Palaeobiogeography and evolution of insular bovids: ecogeographic patterns of body mass variation and morphological changes
Full text linkThe study of the plants and animals that live on island has been a frequent key to understanding the processes of evolution that determine biotic diversity globally. Insular endemic mammals represent a special ground for the study of evolutionary mechanisms and speciation processes in response to the special characteristics of island environments. Endemic bovids are intriguing elements of insular faunas and offer an extensive and diversified sample for exploring patterns of insular evolution of large-sized mammals. This thesis provides the first comprehensive study on the evolution of extinct and living insular bovids, exploring the selective biotic and abiotic factors that influenced ecogeographic patterns of body mass variation and peculiar morphological changes (e.g., hypsodonty and low-gear locomotion) of these taxa.
I show that the majority of island bovids, as large mammals, do follow the main prediction of the island rule, showing a body size reduction, and that ecological release and resource limitation are the main factors influencing body size evolution of these taxa.
My results indicate that hypsodonty (increase in molar crown height), a quite common morphological trend in insular artiodactyls, is shared by the majority of insular bovids independently from the abrasiveness of the current diet. The evolution of this feature appear to result from an expansion of the dietary niche under resource limitation, although alternative, but complementary, hypotheses (e.g., increase in reproductive lifespan/longevity and changes in eating methods) cannot be excluded.
The acquisition of a low-gear locomotion or the maintaining of a cursorial aptitude in insular bovids can be explained in the light of habitat selection (niche availability) and predatory pressure (ecological release) operating on each island.
Finally, my results confirm the crucial role of time in isolation, with each of the above evolutionary phenomena becoming more developed for bovid populations with longer residence times on the islands. Another factor that needs to be mentioned is original bauplan, working as a constraint in the evolution of all the species in the study.
By integrating research into the evolution of body mass variation and peculiar morphological changes exhibited by both extinct and extant bovids, this thesis documents patterns that have often been only hinted at previously, and identifies some that appear to be entirely new, providing new insights into the phenomena of the island syndrome and bovid evolution.2012 SYNTHESYS projects GB-TAF-1787 and DE-TAF-1867 (European Union-funded Integrated Activities grant
How correct is any chronological ordering of the Quaternary Sardinian mammalian assemblages?
No full textThe evolutionary succession of Quaternary Sardinian fauna ( from impoverished but balanced, to disharmonic, strongly impoverished, and highly unbalanced with respect to faunas inhabiting similar continental ecosystems) has already been outlined. Two main faunal complexes ( FCs) and three Quaternary faunal subcomplexes ( FsCs) have been depicted. Each FC/FsC gathers local faunal assemblages (LFAs) showing a fairly high taxonomical similarity. FCs and FsCs succeed each other through time, although their temporal extent is uncertain. Although the chronological ordering of Sardinian FCs/FsCs can be regarded as a fairly satisfactory scheme, we are far from to have a reliable biochronological ordering LFAs. The well-known problem of arranging in a correct chronological order LFAs from the terrestrial domain is amplified in the case of the Sardinian insular impoverished and disharmonic Quaternary faunas. The high discontinuity in the fossiliferous sedimentary record, the rarity of long sedimentary sequences, the scantiness of firm geo-chronological constraints and numerical dates limit the possibility of inferring the relative chronological ordering of LFAs and validate the existence of intraspecific evolutionary trends. Fluctuating patterns in morphology and body size of Quaternary Sardinian species might be present, but they are difficult to ascertain because sedimentary successions giving evidence of the superposition of faunal assemblages are rare, and numerical dates are scanty or missing for some key-sites. As a result, the successions of Quaternary Sardinian LFAs thus far proposed are largely approximate, while FC/FsC can be regarded as the "best-fit" allowed by available data. A more robust and detailed chronological ordering needs more stratigraphic analysis and reliable numerical dating. (C) 2013 Elsevier Ltd and INQUA. All rights reserved
Functional morphology and palaeohabitat predictions: the case study of Plio‐Pleistocene endemic bovids from Sardinia
No full text
Island rule and habitat selection: exploring factors behind the body size reduction of the Javanese fossil bovid Duboisia santeng (Dubois, 1891)
No full text- …
