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on Evolutionary Economics |
| By: | Guillaume Blanc and Romain Wacziarg (Simon Fraser University) |
| Abstract: | For most of human history, until the fertility transition, technological progress translated into larger populations, preventing sustained improvements in living standards. We argue that migration offered an escape valve from these Malthusian dynamics after the European discovery and colonization of the Americas. We document a strong relationship between fertility and migration across countries, regions, individuals, and periods, in a variety of datasets and specifications, and with different identification strategies. During the Age of Mass Migration, persistently high fertility across much of Europe created a large reservoir of surplus labor that could find better opportunities in the New World. These migrations, by relieving demographic pressures, accelerated the transition to modern growth. |
| Date: | 2026–03 |
| URL: | https://d.repec.org/n?u=RePEc:sfu:sfudps:dp26-05 |
| By: | Cheikbossian, Guillaume; Peña, Jorge |
| Abstract: | We study the evolution of other-regarding preferences in a public goods game where the production function exhibits varying degrees of complementarity between individual efforts. Individuals are rational agents who play a Nash equilibrium, but differ in the weight they assign to others’ payoffs, capturing varying degrees of prosocial or anti-social preferences. This preference trait evolves through payoff-based biased social learning, modeled within an adaptive dynamics framework. Because material payoffs induced by the equilibrium contributions may be non-concave in the preference parameter, evolutionary branching can arise. We show that monomorphic populations are evolutionarily stable only when complementarity between individual efforts is sufficiently strong, in which case preferences converge toward either prosociality or anti-sociality depending on the nature of strategic interactions between players. By contrast, when contributions are highly substitutable, monomorphic populations can become unstable, giving rise to polymorphic populations in which multiple preference types coexist. These results highlight how the structure of the public goods environment shapes the evolution and diversity of other-regarding motivations in culturally evolving populations. |
| Keywords: | Adaptive dynamics; other-regarding preferences; public goods games |
| Date: | 2026–04 |
| URL: | https://d.repec.org/n?u=RePEc:tse:wpaper:131681 |
| By: | Senran Lin |
| Abstract: | This paper proposes a belief-based framework for social norms in environments where individuals choose a single action. Relaxing the assumption that what is appropriate is common knowledge, this framework allows individuals to be uncertain about it, and to hold heterogeneous assessments and beliefs about others' assessments. Within this framework, perceived injunctive social norm, personal values, and empirical expectations, while distinct, are systematically connected through an informational structure. The framework further clarifies how provided information shapes perceived norms: its effect depends on what is disclosed, whether it is publicly or privately revealed, and how the disclosed object encodes underlying information. |
| Date: | 2026–04 |
| URL: | https://d.repec.org/n?u=RePEc:arx:papers:2604.18044 |
| By: | Fabio Galeotti (GATE Lyon Saint-Étienne - Groupe d'Analyse et de Théorie Economique Lyon - Saint-Etienne - UL2 - Université Lumière - Lyon 2 - UJM - Université Jean Monnet - Saint-Étienne - EM - EMLyon Business School - CNRS - Centre National de la Recherche Scientifique); Jona Krutaj (UON - University of Nottingham, UK); Marie Claire Villeval (GATE Lyon Saint-Étienne - Groupe d'Analyse et de Théorie Economique Lyon - Saint-Etienne - UL2 - Université Lumière - Lyon 2 - UJM - Université Jean Monnet - Saint-Étienne - EM - EMLyon Business School - CNRS - Centre National de la Recherche Scientifique) |
| Abstract: | Abandoning detrimental social norms is complex due to the strong pressure to conform. We examine how leaders can guide norm change in heterogeneous societies where individual preferences evolve at different rates. Inspired by the model and experimental design of [J. Andreoni, N. Nikiforakis, and S. Siegenthaler, Proc. Natl. Acad. Sci. U.S.A. 118 , e2014893118 (2021)], we conduct a large-scale laboratory experiment in which we manipulate the speed at which preferences change within a society and introduce leaders with different, evolving preferences. Without leaders, a minority of citizens with rapidly changing preferences cannot overturn an existing norm in a society where most individuals have slow-changing preferences. When fast-changing citizens form the majority, norm change occurs in most groups, but at high welfare costs. In contrast, exogenously selected leaders are highly effective at coordinating expectations and shifting heterogeneous societies toward a more efficient norm—at lower welfare costs and regardless of the underlying distribution of preference evolution across individuals. However, the timing of norm change depends on whether leaders prioritize their preferences (autocratic leadership) or those of the majority (democratic leadership). A follow-up experiment shows that peer-to-peer communication encourages leaders to adopt a more democratic leadership style. These results highlight the pivotal role of leadership in driving norm change and the importance of public voice in shaping leaders' behavior. |
| Keywords: | Laboratory experiment, Tipping threshold, Coordination, Leadership, Social norm |
| Date: | 2026 |
| URL: | https://d.repec.org/n?u=RePEc:hal:journl:hal-05595719 |
| By: | Shuhuai Zhang; Shu Wang; Zijun Yao; Chuanhao Li; Xiaozhi Wang; Songfa Zhong; Tracy Xiao Liu |
| Abstract: | Altruism is fundamental to human societies, fostering cooperation and social cohesion. Recent studies suggest that large language models (LLMs) can display human-like prosocial behavior, but the internal computations that produce such behavior remain poorly understood. We investigate the mechanisms underlying LLM altruism using sparse autoencoders (SAEs). In a standard Dictator Game, minimal-pair prompts that differ only in social stance (generous versus selfish) induce large, economically meaningful shifts in allocations. Leveraging this contrast, we identify a set of SAE features (0.024% of all features across the model's layers) whose activations are strongly associated with the behavioral shift. To interpret these features, we use benchmark tasks motivated by dual-process theories to classify a subset as primarily heuristic (System 1) or primarily deliberative (System 2). Causal interventions validate their functional role: activation patching and continuous steering of this feature direction reliably shift allocation distributions, with System 2 features exerting a more proximal influence on the model's final output than System 1 features. The same steering direction generalizes across multiple social-preference games. Together, these results enhance our understanding of artificial cognition by translating altruistic behaviors into identifiable network states and provide a framework for aligning LLM behavior with human values, thereby informing more transparent and value-aligned deployment. |
| Date: | 2026–04 |
| URL: | https://d.repec.org/n?u=RePEc:arx:papers:2604.19260 |
| By: | Shaun Hargreaves Heap; Mehmet Mars Seven |
| Abstract: | We study whether zero-sum decision rules, maximin and minimax, harm agents' interests in positive-sum strategic environments relative to Nash equilibrium behavior or, more generally, than best response behaviour. Contrary to an influential evolutionary view, we give illustrations where maximin serves an agent's interests better than Nash equilibrium behaviour. We also show that these illustration are not atypical or idiosyncratic because, in our main result, the class of such games where a maximin profile strictly Pareto dominates all Nash equilibria has the same cardinality as the class of games in which a Nash equilibrium strictly Pareto dominates all maximin profiles. Thus, neither behavior is generally superior. We further identify additional mechanisms favoring maximin over Nash equilibrium, including coordination failures under multiple equilibria, where maximin can outperform Nash play in realised-pay-off terms. A systematic analysis of strictly ordinal symmetric 3x3 games shows that these effects arise with non-trivial frequency. Our findings, therefore, suggest that the observed rise in zero-sum thinking in many rich countries, when associated with a maximin decision rule, will not be readily displaced through its generation of inferior pay-offs. |
| Date: | 2026–04 |
| URL: | https://d.repec.org/n?u=RePEc:arx:papers:2604.19359 |