Learning from Neighbours

When payoffs from different actions are unknown, agents use their own past experience as well as the experience of their neighbours to guide their decision making. In this paper, we develop a general framework to study the relationship between the structure of these neighbourhoods and the process of social learning.
We show that, in a connected society, local learning ensures that all agents obtain the same payoffs in the long run. Thus, if actions have different payoffs, then all agents choose the same action, and social conformism obtains. We develop conditions on the distribution of prior beliefs, the structure of neighbourhoods and the informativeness of actions under which this action is optimal. In particular, we identify a property of neighbourhood structures—local independence—which greatly facilitates social learning. Simulations of the model generate spatial and temporal patterns of adoption that are consistent with empirical work.     

Conformism and cooperation in a local interaction model

We analyze a local interaction model where agents play a bilateral prisoner’s dilemma game with their neighbors. Agents learn about behavior through payoff-biased imitation of their interaction neighbors (and possibly some agents beyond this set). We find that the Eshel et al. (Am Econ Rev 88:157–179, 1998) result that polymorphic states are stochastically stable in such a setting is not robust. In particular, whenever agents use information also of some agents beyond their interaction neighbors, the unique stable outcome is one where everyone chooses defection. Introducing a sufficiently strong conformist bias into the imitation process, we find that full cooperation always emerges. Conformism is thus identified as a new mechanism that can stabilize cooperation.

Play locally,learn globally: group selection and structural basis of cooperation

In group-structured populations, altruistic cooperation among unrelated group members may be sustainable even when the evolution of behavioral traits is governed by a payoff-based replicator dynamic. This paper explores the importance in this dynamic of two aspects of group structure: global or local interaction in a public goods game and global or local cultural transmission (learning) of behavioral traits. To clarify the underlying dynamic, I derive an extension of the Price equation for the decomposition of changes in the population frequency of a binary trait. I use this to analyze the effect of different structures of interaction and learning on within- and between-group variances of the frequency of cooperative behaviors and thereby on the evolution of cooperation. Of the four population structures given by global/local learning and global/local interaction, local interaction with global learning provides the most favorable environment for the evolution of cooperation. This combination of learning and interaction structures supports a high level of between-group variance in the frequency of cooperative types, so that most cooperators benefit from being in groups composed mostly of cooperators. However, while global learning is essential to the evolution of cooperation, cooperation is more robust when learning is not entirely global because local learning process, ironically, limits the extent to which defectors can free ride on cooperative group members.      

Rage against the machines: how subjects play against learning algorithms

We use a large-scale internet experiment to explore how subjects learn to play against computers that are programmed to follow one of a number of standard learning algorithms. The learning theories are (unbeknown to subjects) a best response process, fictitious play, imitation, reinforcement learning, and a trial & error process. We explore how subjects’ performances depend on their opponents’ learning algorithm. Furthermore, we test whether subjects try to influence those algorithms to their advantage in a forward-looking way (strategic teaching). We find that strategic teaching occurs frequently and that all learning algorithms are subject to exploitation with the notable exception of imitation.     

Imitation—theory and experimental evidence

We introduce a generalized theoretical approach to study imitation and subject it to rigorous experimental testing. In our theoretical analysis we find that the different predictions of previous imitation models are mainly explained by different informational assumptions, and to a lesser extent by different behavioral rules. In a laboratory experiment we test the different theories by systematically varying information conditions. We find significant effects of seemingly innocent changes in information. Moreover, the generalized imitation model predicts the differences between treatments well. The data provide support for imitation on the individual level, both in terms of choice and in terms of perception. Furthermore, individuals’ propensity to imitate more successful actions is increasing in payoff differences.     

Factors explaining inter-municipal cooperation in service delivery: a meta-regression analysis

Inter-municipal cooperation is an important public service delivery reform, whose drivers move beyond simple concerns with costs and economic efficiency, to policy issues related to governance structure and spatial context. We conduct a meta-regression analysis based on the existing multivariate empirical literature to explore what factors explain divergence in results in the existing empirical studies. We find strong evidence that fiscal constraints, spatial, and organizational factors are significant drivers of cooperation. Our meta-regressions do not yield results to explain divergence in results on community wealth, economies of scale, or racial homogeneity. More studies on these factors are needed to understand how these factors might affect cooperation. Future theoretical and empirical research should give more attention to spatial and organizational factors to develop a better understanding of factors driving cooperation, and how they differ across local government structures and regions.     

A One-Stage Model of Link Formation and Payoff Division

In this paper we introduce a strategic form model in which cooperation structures and divisions of the payoffs are determined simultaneously. We analyze the cooperation structures and payoff divisions that result according to Nash equilibria, strong Nash equilibria, and coalition proof Nash equilibria. We find that no cycle will be formed if a player claims a positive amount for the formation of one of its links and that a player does not necessarily profit from a central position in a cooperation structure. Journal of Economic Literature Classification Numbers: C71, C72.     

Preferences and beliefs in a sequential social dilemma: a within-subjects analysis

In empirical analyses of games, preferences and beliefs are typically treated as independent. However, if beliefs and preferences interact, this may have implications for the interpretation of observed behavior. Our sequential social dilemma experiment allows us to separate different interaction channels. When subjects play both roles in such experiments, a positive correlation between first- and second-mover behavior is frequently reported. We find that the observed correlation primarily originates via an indirect channel, where second-mover decisions influence beliefs through a consensus effect, and the first-mover decision is a best response to these beliefs. Specifically, beliefs about second-mover cooperation are biased toward own second-mover behavior, and most subjects best respond to stated beliefs. However, we also find evidence for a direct, preference-based channel. When first movers know the true probability of second-mover cooperation, subjects' own second moves still have predictive power regarding their first moves.     

特殊区域旅游合作与发展的经验与启示——以粤港澳区域为例

粤港澳大珠江三角洲区域地理环境的整体性和差异性造就了丰富多样、互补性强的旅游资源和旅游产品,经历了30年的旅游合作,探索出了三种旅游合作模式,形成了五个既相互独立又相互联系的次级旅游区域。粤港澳区域旅游合作是其内部特性、层次、结构、水平不同的各次区域之间形成的层次有别、关系密切、结构复杂、内涵丰富的旅游空间体系的过程。其旅游合作的形式和内容包括了旅游资源—产品—市场联合开发、旅游交通—设施—信息系统合作兴建、旅游政策—制度—管理协作交流、旅游人才—技术—资本流动与融合等方面。粤港澳区域旅游合作的成功经验所提供的启示主要有:粤港澳区域的复杂性和差异性是挑战与机遇并存,其旅游合作成效显著;市场机制和政府协调缺一不可;提升、优化与完善是区域旅游合作高级化的必然途径,即发展目标上提升、空间结构上优化和区域功能上完善。     

Identifying spatial interactions in the presence of spatial error autocorrelation: An application to land use spillovers

Spatial spillovers—interaction effects among neighboring agents in space—are a common characteristic of a variety of processes that are of interest to environmental and resource economists. Empirical identification of these interactions is challenging, however, due to the endogenous nature of the interactions and the inevitable unobserved spatial correlation that, if uncontrolled, can result in spurious estimates of the interaction parameters. Traditional spatial econometric models rely on maintained assumptions that impose separate structures for the spatial error and interaction processes and thus are insufficient for solving this identification problem. To identify spatial land use spillovers in a hedonic model of residential housing values, we pursue an alternative approach by exploiting a natural experiment in the data. We use exogenous physical land features that impose a direct constraint on residential development on some, but not all, of the land that falls within our study region and use this to construct a “partial population identifier.” We find that this estimation strategy solves the endogeneity problem and reduces spatial error autocorrelation, but does not fully eliminate it. Estimation of the model using a more restricted sample in combination with the partial population identification strategy is successful in eliminating the remaining spatial error autocorrelation. We conclude that less restrictive approaches to controlling for unobserved spatial correlation, such as the natural experiment pursued here, may provide a superior alternative to identifying spatial spillovers.     

Foreign Direct Investment and the Incentives to Innovate and Imitate*

We propose a new channel of FDI spillovers on domestic firms, which operates through imitation of original products. Domestic heterogeneous firms may not introduce any new products, introduce a new product line (innovate), or develop a variety that is a close substitute to an existing product line (imitate). The presence of foreign firms generates incentives for imitation because they introduce original products that are vertically differentiated from domestic products. Using firm‐level panel data for China, we find that increased FDI presence in a given industry leads to more imitation, but not necessarily more innovation, by domestic firms.     

On innovation cycles in a finite discrete R&D game

This paper shows that innovation (or Schumpeter's) cycles can be demonstrated in a discrete and finite dynamic game of innovation and imitation. We find that the cycles depend crucially on whether imitation is a credible threat and hence, we conclude that strategic interactions are sufficient to generate cycles in an innovation game.     

Private patent protection in the theory of Schumpeterian growth

We develop a Schumpeterian growth model with privately optimal intellectual property rights (IPRs) enforcement and investigate the implications for intellectual property and R&D policies. In our setting, successful innovators undertake costly rent protection activities (RPAs) to enforce their patents. RPAs deter innovators who seek to discover higher quality products and thereby replace the patent holder. RPAs also deter imitators who seek to capture a portion of the monopoly market by imitating the patent holder's product. We investigate the role of private IPR protection by considering the impact of subsidies to RPAs on economic growth and welfare. We find that a larger RPA subsidy raises the innovation rate if and only if the ease of imitation is above a certain level. With regards to welfare, we find that depending on the parameters it may be optimal to tax or subsidize RPAs. Thus a prohibitively high taxation of RPAs is not necessarily optimal. We also show that the presence of imitation strengthens the case for subsidizing R&D.     

Learning to choose a commodity-money: Carl Menger's theory of imitation and the search monetary framework

This paper studies Carl Menger's theory of the emergence of a commodity money. We propose an interpretation of Menger's learning by imitation process based on the search theoretical formal framework. We show that there exists a tension between the importance of intrinsic properties of commodities and the pure conventional self-fulfilling expectations of agents. This confirms the role of imitation in the emergence of monetary equilibria in search theory. We conclude that Menger's approach may support the idea that the fundamental property of a commodity-money (namely its great liquidity) is the result of its emergence process and not necessarily of its original intrinsic properties.     

Confusion and learning in the voluntary contributions game

We use a limited information environment to assess the role of confusion in the repeated voluntary contributions game. A comparison with play in a standard version of the game suggests, that the common claim that decision errors due to confused subjects biases estimates of cooperation upwards, is not necessarily correct. Furthermore, we find that simple learning cannot generate the kind of contribution dynamics commonly attributed to the existence of conditional cooperators. We conclude that cooperative behavior and its decay observed in public goods games is not a pure artefact of confusion and learning.     

Imitation and the evolution of Walrasian behavior: Theoretically fragile but behaviorally robust

A well-known result by Vega-Redondo (1997) [18] implies that in symmetric Cournot oligopolies, imitation leads to the Walrasian outcome. We show that this result is not robust to the slightest asymmetry in costs, since every outcome where agents choose identical actions will be played some fraction of the time in the long run. We then conduct experiments to check this fragility. We obtain that, contrary to the theoretical prediction, the Walrasian outcome is a good predictor of market outcomes. Finally, we suggest a new theory based on a mix of imitation and other learning processes that explains subjects' behavior fairly well.     

Innovation,imitation and multinationalisation in a North–South model: a theoretical note

We consider a dynamic general equilibrium product variety model of international product cycle with endogenous rate of imitation in the South; and find that a policy of strengthening intellectual property rights (IPR) protection in the South lowers the rate of product innovation, rate of multinationalisation and South–North relative wage if multinationalisation [or, foreign direct investment (FDI)] is the channel of production transfer. These results are significantly different from those obtained in the exogenous imitation model of Lai (J Dev Econ 55(1): 133–153, 1998). So a stronger IPR protection policy adopted by the South may not be interpreted as an incentive to encourage Northern FDI in the South and to raise the rate of innovation in the North.      

Social capital and social learning after Hurricane Sandy

The post-disaster context is one characterized by profound uncertainty. Those affected by the storm, or earthquake, or flood, must determine what strategies to pursue in response to the disaster and must find ways to coordinate their recovery efforts with others in their community. Ex ante it is not clear what strategies will be most effective. If communities are to recover after a disaster, community members must engender and engage in a process of social learning involving experimentation, communication, and imitation. This paper explores the post-disaster social learning process. Specifically, we focus on the importance of social capital in facilitating social learning after a disaster, including facilitating community members’ ability to communicate their desire to return, to assess damage, to overcome barriers to rebuilding through collective yet voluntary action, and to learn from and imitate others’ successes. Focusing on how this process took place after Hurricane Sandy in Rockaway, New York, especially within the Orthodox Jewish community, we examine how community groups (a) adapted existing organization structures and (b) created new procedures and imitated the successful actions of others in order to spur recovery.     

Discrimination via Exclusion: An Experiment on Group Identity and Club Goods

We study using laboratory experiments the impact on cooperation of allowing individuals to invest in group‐specific, excludable public goods. We find that allowing different social groups to voluntarily contribute to such goods increases total contributions. However, a significant proportion of that contribution goes toward the group‐specific club good rather than the public good, even when the latter has higher financial returns to cooperation. We find significant evidence of in‐group biases, which are manifested by positive in‐group reciprocity. That is, club goods allow subjects to display their preferences for interaction with their in‐group members, as well as positive in‐group reciprocity.     

Neighbourhood and Family Effects in Educational Progress

Increasing inequality in Australian cities has created the need for a deeper understanding of the interaction between spatial segmentation and economic outcomes. This paper offers a preliminary economic analysis of Australian neighbourhood externalities in the context of increasing segmentation. Theoretically, neighbourhoods can affect youths' economic out-comes through their effects on school quality, information flows, job networks, and demonstration effects. We utilise a new survey of 171 year 12 students in ten Melbourne high schools to examine the impact of individual, family, and neighbourhood characteristics on the decision to attend post-secondary education. It is shown that there exist neighbourhood externalities that affect human capital investment decisions. Finally, we offer some tentative implications for public policy.