Silly Rules Enhance Learning of Compliance and Enforcement Behavior in Artificial Agents

Abstract : How do societies learn and maintain social norms? Here we use multi-agent reinforcement learning to investigate the learning dynamics of enforcement and compliance behaviors. Artificial agents populate a foraging environment and need to learn to avoid a poisonous berry. Agents learn to avoid eating poisonous berries better when doing so is taboo, meaning the behavior is punished by other agents. The taboo helps overcome a credit-assignment problem in discovering delayed health effects. By probing what individual agents have learned, we demonstrate that normative behavior relies on a sequence of learned skills. Learning rule compliance builds upon prior learning of rule enforcement by other agents. Critically, introducing an additional taboo, which results in punishment for eating a harmless berry, further improves overall returns. This “silly rule” counterintuitively has a positive effect because it gives agents more practice in learning rule enforcement. Our results highlight the benefit of employing a computational model focused on learning to implement complex actions.

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The Economic Origins of Trust: Evidence from Mobile Pastoralism

Abstract : We examine the hypothesis from anthropology that the economic requirements of mobile pastoralism made pastoralists highly interdependent within groups but hostile to individuals beyond the radius of extended kin. We find that historical reliance on mobile pastoralism led to the emergence of in-group oriented and family-centered individuals. Specifically, mobile pastoralism explains part of the contemporary variation in in-group relative to out-group trust. This result is valid across countries, between residents of the same country, among second-generation migrants and with an instrumental variable strategy. We also examine the implications of this cultural trait for cooperation and firm development. In a quasi-experimental setting, we find that individuals from mobile pastoralist groups are perceived as more hostile and suspicious. Additionally, we find that greater reliance on mobile pastoralism is associated with less objective promotion criteria within firms and smaller firm size, suggesting that in-group trust bias may affect firm development. This paper contributes to our understanding of how forms of economic production shape the scope and extent of trust.

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Celestial Enlightenment: Eclipses, Curiosity and Economic Development Among Pre-modern Ethnic Groups

Abstract : This paper revisits the role of human capital for economic growth among pre-modern ethnic groups. We hypothesize that exposure to rare natural events drives curiosity and prompts thinking in an attempt to comprehend and explain the phenomenon, thus raising human capital and, ultimately, pre-modern growth. We focus on solar eclipses as one particular trigger of curiosity and empirically establish a robust relationship between their number and several proxies for economic prosperity: social complexity, technological level and population density. Variation in solar eclipse exposure is exogenous as their local incidence is randomly and sparsely distributed all over the globe. Additionally, eclipses' non-destructive character makes them outperform other uncanny natural events, such as volcano eruptions or earthquakes, which have direct negative economic effects. We also offer evidence compatible with the human capital increase we postulate, finding a more intricate thinking process in ethnic groups more exposed to solar eclipses. In particular, we study the development of written language, the playing of strategy games and the accuracy of the folkloric reasoning for eclipses.

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Do Disasters Affect the Tightness of Social Norms?

Abstract : Universally, social norms prescribe behavior and attitudes, but societies differ widely in how strictly individuals hold to the norms and sanction those who do not. This paper shows that large adverse events, henceforth “disasters”, lead to tighter social norms. To establish this result, I combine data on the occurrences of conflicts, epidemics, and natural and economic disasters with the World Value Surveys, European Social Surveys, and Gallup World Polls. I use this data set to estimate the effect of disasters on the tightness of social norms in two ways: (i) investigating event-studies that compare individuals interviewed in the weeks before and after the same disaster; and (ii) examining variation in individuals’ past exposure to disasters across countries and cohorts while controlling for country-, cohort-, and life-cycle-specific factors. The event-studies demonstrate that disasters tighten social norms by 9 percent of a standard deviation. The analysis of cross-country variation shows that the effect can persist for decades and is transmitted to the subsequent generation. The results are consistent with a conceptual framework in which disasters increase the returns to coordination within groups and suggest that past exposure to disasters partially explains within-group cohesion and intolerance for non-conformism.

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