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on Evolutionary Economics |
| By: | Maxime Menuet (Université Côte d'Azur, CNRS, GREDEG, France) |
| Abstract: | This paper studies how the temporal structure of adjustment shapes evolutionary dynamics in symmetric games. We introduce a fractional replicator dynamic that modifies the classical replicator only through the time operator, replacing the ordinary derivative with a fractional derivative of order α ∈ (0, 1]. This formulation preserves payoff monotonicity, feasibility, and the equilibrium set, while allowing past payoff differences to affect current behavior through long memory with power-law decay. We show that fractional time fundamentally alters local stability and equilibrium selection. While evolutionarily stable strategies remain locally asymptotically stable, equilibria that are unstable under the classical replicator can become locally stable when memory is sufficiently persistent, generating stability switching and purely temporal bifurcations without any change in payoffs or strategic interaction. Moreover, convergence toward stable equilibria becomes polynomial rather than exponential, implying slow adjustment even in simple games. As a consequence, equilibrium selection may fail to be completed over economically relevant horizons despite being guaranteed asymptotically. Finally, we provide a microfoundation based on standard payoff-monotone revision processes with heterogeneous and asynchronous revision opportunities. Fractional dynamics thus offer a parsimonious way to incorporate persistent memory into evolutionary models while preserving their core economic structure. |
| Keywords: | Fractional replicator dynamics; Evolutionary game theory; Fractional calculus; Long memory; Stability switching; Equilibrium selection |
| JEL: | C72 C73 |
| Date: | 2026–02 |
| URL: | https://d.repec.org/n?u=RePEc:gre:wpaper:2026-05 |
| By: | Becker, Sascha O. (University of Oxford); Panin, Amma (Université catholique de Louvain, LIDAM/CORE, Belgium); Pfaff, Steven; Rubin, Jared |
| Abstract: | This chapter examines the role of religion in economic development, both historically and today. Religion's influence varies globally, with high religiosity in countries like Pakistan and low rates in China. Despite declines in some Western countries, religion remains influential worldwide, with projected growth in Muslim populations due to higher fertility rates. Religion continues to shape societal norms and institutions, such as education and politics, even after its direct influence fades. The chapter explores how religious institutions and norms have impacted economic outcomes, focusing on both persistence and decline. It also examines cultural transmission, institutional entrenchment, networks, and religious competition as mechanisms sustaining religion's influence. We explore the relationship between religion and secularization, showing that economic development does not always reduce religiosity. Lastly, the chapter highlights gaps in the literature and suggests future research areas on the evolving role of religion in economic development. |
| Keywords: | Religion ; Economic Development ; Religiosity ; Cultural Transmission ; Secularization ; Historical Persistence ; Religious Competition ; Networks ; Social Norms |
| JEL: | D85 I25 J10 N30 O33 O43 P48 Z10 Z12 |
| Date: | 2025–03–01 |
| URL: | https://d.repec.org/n?u=RePEc:cor:louvco:2025006 |
| By: | Douglas K.G. Araujo; Harald Uhlig |
| Abstract: | As Large Language Models (LLMs) are increasingly tasked with autonomous decision making, understanding their behavior in strategic settings is crucial. We investigate the choices of various LLMs in the Ultimatum Game, a setting where human behavior notably deviates from theoretical rationality. We conduct experiments varying the stake size and the nature of the opponent (Human vs. AI) across both Proposer and Responder roles. Three key results emerge. First, LLM behavior is heterogeneous but predictable when conditioning on stake size and player types. Second, while some models approximate the rational benchmark and others mimic human social preferences, a distinct “altruistic” mode emerges where LLMs propose hyper-fair distributions (greater than 50%). Third, LLM Proposers forgo a large share of total payoff, and an even larger share when the Responder is human. These findings highlight the need for careful testing before deploying AI agents in economic settings. |
| JEL: | C70 C90 D91 |
| Date: | 2026–03 |
| URL: | https://d.repec.org/n?u=RePEc:nbr:nberwo:34919 |
| By: | Stark, Oded; Kosiorowski, Grzegorz |
| Abstract: | We establish a new approach to the modeling of cooperation, and we formulate a new solution concept for cooperative games. We do this by constructing a game of cooperation between individuals who exhibit distaste for relative deprivation, RD, in the sense that they experience stress when their income is lower than that of their comparators. In such a game, the sharing out of the jointly earned income between these individuals when they cooperate, as prescribed by standard solutions of cooperative games, might not be acceptable to the individuals. The stress from RD may have the upper hand. Measuring stress by RD, we thus model a setting in which two individuals who are concerned with being relatively deprived need to decide whether or not to cooperate. We term this setting an RD cooperative game, and we design a rule, the RD solution, for the distribution of the income yielded in this game. The RD solution prescribes cooperation in spite of cooperation-induced stress and preserves the spirit of standardness (an equal sharing of the gain that accrues from cooperation) for two-player games (a property shared by the main solution concepts for cooperative games). |
| Keywords: | Institutional and Behavioral Economics |
| Date: | 2026–03–17 |
| URL: | https://d.repec.org/n?u=RePEc:ags:ubzefd:396310 |
| By: | Gregory Clark (University of Southern Denmark, Danish Institute for Advanced Study, and LSE); Martin Hørlyk Kristensen (University of Southern Denmark) |
| Abstract: | There is continued debate, with important social consequences, about how social status is transmitted between parents and children. In particular, how much does genetics as opposed to social causation matter? In an ingenious recent article, Collado et al. (2023), using an extended family lineage from Sweden and the outcome of years of education, claim that outcome correlations across relatives are inconsistent with genetic transmission. In contrast, Clark (2023) claims that a simple 3-parameter additive genetic model of social outcomes predicts well correlations as remote as 4th cousins in a stable way for England 1600-2022. In this paper we show that the genetic model of Clark (2023) fits the correlation in educational attainment for extended sets of relatives in modern Denmark and Sweden as well as the 20-parameter social causation model of Collado et al. Further, the parameter values in the genetic model for Denmark and Sweden are similar to those found for a variety of social outcomes in both pre-industrial and modern England. |
| Keywords: | intergenerational mobility, social mobility, assortative mating, genetic transmission |
| JEL: | J62 J12 D31 I24 |
| Date: | 2026–03 |
| URL: | https://d.repec.org/n?u=RePEc:hes:wpaper:0299 |