Evolutionary Economics http://lists.repec.org/mailman/listinfo/nep-evo Evolutionary Economics 2026-03-09 Family Institutions and the Global Fertility Transition https://d.repec.org/n?u=RePEc:hal:journl:hal-05496893&r=&r=evo Much of the observed cross-country variation in fertility aligns with the predictions of classic theories of the fertility transition: countries with higher levels of human capital, higher GDP per capita, or lower mortality rates tend to exhibit lower fertility. However, when examining changes within countries over the past 60 years, larger fertility declines are only weakly associated with greater improvements in human capital, per capita GDP, or survival rates. To understand why, we focus on the role of family institutions, particularly marriage and inheritance customs. We argue that, together with the diffusion of cultural norms, they help explain variations in the timing, speed and magnitude of the fertility decline. We propose a stylized model integrating economic, health, institutional and cultural factors to study how these factors interact to shape fertility transition paths. We find that family institutions can mediate the effect of economic development by constraining fertility responses. Paula E Gobbi Anne Hannusch Pauline Rossi 2026-02-01 Cultural Transmission, Property Rights, and Treatment of the Elderly https://d.repec.org/n?u=RePEc:wes:weswpa:2026-002&r=&r=evo We study how property rights over land, capital, and output interact with cul-tural transmission to determine the welfare of the elderly. In our model, respect for the elderly emerges endogenously: adults transmit norms of care to children, which children later reciprocate when they become adults. We compare regimes of insecure rights over produced goods with secure rights over productive resources, showing that both can sustain elderly well-being through distinct channels. By distinguishing be-tween property rights to outputs and to inputs—and further between fixed and created resources—we uncover nonlinear interactions between cultural transmission, property institutions, and production technologies, and a general curvilinear pattern where the elderly are relatively better off compared to the middle-aged in either an insecure prop-erty right (i.e., common resources) regime or a high productive property rights regime relative to intermediate cases. Ethnographic evidence illustrates these mechanisms and helps explain cross-societal variation in elderly support. The model also demonstrates how demographic, technological, and policy changes can alter the conditions for elderly well-being across stages of development. Matthew J. Baker Joyce P. Jacobsen treatment of the elderly, overlapping generations, property rights, cultural transmission, intergenerational transfers 2026-01 Selection and evolutionary growth in pre-industrial Germany https://d.repec.org/n?u=RePEc:ehl:wpaper:137404&r=&r=evo Evolutionary growth theory (i.e., Galor and Moav (2002) and Clark (2007)) posits that natural selection set the stage for modern growth. I leverage micro-data from historical Germany to assess the viability of the selection mechanisms. I estimate fertility differentials and the inter-generational transmission of SES. High status couples, proxied by occupation, had 1-2 additional children, and SES was strongly heritable. To explore whether these parameters induce selection, I simulate an overlapping generation model of fertility choice and status transmission. The German parameters do not enable Clark’s survival of the richest, whereas Galor and Moav’s selection on quality can arise if the returns to investing in child quality are sufficiently large. Monte Carlo simulations extend the analysis beyond Germany. Survival of the richest requires exceptionally high coefficients of transmission (≈0.87), and selection on quality emerges whenever returns to quality investments translate into higher fertility. Both depend on the strong heritability of the growth-complementary traits. Ohler, Johann socioeconomic status; fertility; inter-generational mobility; endogenous growth theory; survival of the riches; historical demography 2026-01 How does AI distribute the pie? Large Language Models and the Ultimatum Game https://d.repec.org/n?u=RePEc:bfi:wpaper:2026-29&r=&r=evo As Large Language Models (LLMs) are increasingly tasked with autonomous decisionmaking, 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. Douglas K.G. Araujo Harald Uhlig Ultimatum Game, LLM, AI Agents, Behavioral Economics, Algorithmic Decision Making 2026 Do Socioeconomic Disparities Shape Norm Enforcement? https://d.repec.org/n?u=RePEc:hal:cesptp:hal-05368602&r=&r=evo We investigate how socioeconomic disparities shape the enforcement of norms when observing third-party dishonesty. In an online Die-under-the-Cup (DUTC) experiment with a socioeconomically and geographically diverse sample of 720 participants from the French population, observers repeatedly evaluate reports from socioeconomically close and distant counterparts and can punish or reward them without affecting their own payoffs. We classify participants into three socioeconomic tiers using (i) a contextual measure based on average income in the locality of residence and (ii) a relative measure capturing individual income relative to the locality average. To summarise dishonest reporting patterns in this private-report environment, we introduce an observer-level proxy of suspicious reports. Results show that enforcement responds sharply to this proxy, as observers punish more and reward less as suspicion rises. Whether enforcement is socially selective depends on how distance is measured. Under the contextual measure, we find little evidence that close and distant counterparts are treated differently at comparable suspicion levels. Under the relative measure, selectivity emerges through responsiveness: punishment escalates more and rewards drop more strongly as suspicion increases when counterparts are socioeconomically distant. Finally, decomposing pairings by socioeconomic tiers reveals asymmetric enforcement along the hierarchy: holding suspicion constant, observers punish more and reward less when the counterpart is below them in socioeconomic status. In sum, the paper shows that how we measure socioeconomic distance is relevant for norm enforcement—highlighting a channel through which enforcement can reproduce inequality. Irving Argaez Corona Béatrice Boulu-Reshef Jean-Christophe Vergnaud socioeconomic status, Social closeness, norm enforcement, observability, third-party punishment, third-party reward, income levels, Socioeconomic inequality 2025-12-01 Natural disasters and cooperation under diversity: Evidence from Hurricane Harvey https://d.repec.org/n?u=RePEc:zbw:cbscwp:337494&r=&r=evo How does diversity affect cooperation after natural disasters? Drawing on an original survey of Houston-area households and two survey experiments, we find that diversity is associated with lower levels of impersonal cooperation-beyond family and friends-before natural disasters and with lower cooperation both before and after disasters. In affected areas, households in more diverse tracts report receiving less help and express lower support for recovery policies. In a policy experiment, affected respondents typically favor more costly recovery measures, but this preference weakens in high-diversity areas. A second experiment uncovers strong post-disaster ingroup biases along partisan and religious lines, while shared membership in civic associations emerges as a critical facilitator of cooperation in diverse settings. Taken together, these findings demonstrate that diversity can impede post-disaster cooperation and illuminate how social identities shape cooperation and recovery efforts. Balán, Pablo Pinto, Pablo M. Vallejo, Agustín 2025