David Poza

Mesoscopic Effects in an Agent-Based Bargaining Model in Regular Lattices

The effect of spatial structure has been proved very relevant in repeated games. In this work we propose an agent based model where a fixed finite population of tagged agents play iteratively the Nash demand game in a regular lattice. The model extends the multiagent bargaining model by Axtell, Epstein and Young [1] modifying the assumption of global interaction. Each agent is endowed with a memory and plays the best reply against the opponents most frequent demand. We focus our analysis on the transient dynamics of the system, studying by computer simulation the set of states in which the system spends a considerable fraction of the time. The results show that all the possible persistent regimes in the global interaction model can also be observed in this spatial version. We also find that the mesoscopic properties of the interaction networks that the spatial distribution induces in the model have a significant impact on the diffusion of strategies, and can lead to new persistent regimes different from those found in previous research. In particular, community structure in the intratype interaction networks may cause that communities reach different persistent regimes as a consequence of the hindering diffusion effect of fluctuating agents at their borders.

Social Interaction in Hunter-Gatherer Societies: Simulating the Consequences of Cooperation and Social Aggregation

This article describes the design and operation of an agent-based model that represents aspects of hunter-gatherer subsistence, technology, and cultural identity. The agents (representing families or households) in the model interact in a world that has a seasonally variable resource density. Agents must collect resources every step, either independently (by “gathering”) or with cooperation from neighboring agents (“hunting”). Several parameters affect cooperation: understanding these effects is one of the main focus of this article. Another focus is understanding the effects of cooperation in terms of cultural diversity/homogeneity. Some input parameters are historically and ethnographically calibrated, and the results are contrasted, with ongoing archaeological research of Patagonian hunter-gatherers (from 7000 BC or even earlier to 19th century). Specific research questions include how do processes of convergence and divergence occur between groups of hunter-gatherers over the long term? How could the autonomous local interactions of heterogeneous bounded rational agents generate this kind of regularity? What role outside influence plays on the formation of ethnic identities? Our aim is to integrate the state-of-the-art knowledge from different social sciences and technological developments into a fruitful approach to develop sociohistorical studies

Evolution of Equity Norms in Small-World Networks

The topology of interactions has been proved very influential in the results of models based on learning and evolutionary game theory. This paper is aimed at investigating the effect of structures ranging from regular ring lattices to random networks, including small-world networks, in a model focused on property distribution norms. The model considers a fixed and finite population of agents who play the Nash bargaining game repeatedly. Our results show that regular networks promote the emergence of the equity norm, while less-structured networks make possible the appearance of fractious regimes. Additionally, our analysis reveals that the speed of adoption can also be affected by the network structure.

Simulating Patagonian Territoriality in Prehistory: Space, Frontiers and Networks Among Hunter-Gatherers

In the last 40 years, the very idea of ethnicity has evolved from a static and essentialist classification of human groups according to their immutable “nature” to a relational frame of reference used by groups of people to consider themselves “similar” or to be explicitly differentiated by others. Nevertheless, the growing importance of variability analysis of mitochondrial DNA and other biological markers in modern prehistoric studies, with their emphasis on the identification of geographic patterns in genetic and phenotypic diversity of prehistoric populations is going in the opposite direction, as if the existence of genetic variability in the past would be comparable to what is inferred about cultural variation in the present. In this paper we have built a computer simulation of economic processes causing social aggregation, territoriality and ethnogenesis among Patagonian hunter-gatherers. We argue that cultural similarity and the constriction of groups to a restricted geographical area are not necessarily ethnic markers. Our model suggests that the more inter-generational knowledge transmission among socially aggregated individuals in the past, the greater the similarity in the social activity performed by agents in the present, and the same for their territoriality and the way frontiers and social networks were negotiated. Our computer simulation intends to answer the question “Why did human groups modify their traditional residence mobility and dispersal patterns?” In ancient Patagonia, at the extreme south of South America, from 12,000 BC until nineteenth century AD, this social transformation seems to coincide with slow changes in subsistence economy and technology. However, there are historical and archaeological sources that suggest this process was related with increased social complexity: wars and conflicts between different indigenous groups would have preceded this new scenario, even before European contact.

New Insights on the Emergence of Classes Model

We show the results of a detailed replication of the Emergence of Classes Model Axtell et al. (2004). We study the effect of possible biases on the original proposal and we find additional results and conclusions. We also explore the effects of minor changes on the decision rules that agents play.

Impact of Tag Recognition in Economic Decisions

In this paper we replicate the model by Axtell et al. (2000), a game where two agents ask for proportions of the same pie. After simulating the same scenarios, we get the same results, both in the cases of one-agent and two-agent types (tag model). Once we know the model has been properly replicated, we go one step further, by analyzing the influence in the observed behavior of the ‘rational’ decision rule and of the matrix payoff. First, we change the agent’s decision rule, so that agents could decide playing a heuristic which is not so ‘rational’ as the original rule. We also evaluate the dependence of the results on the selected payoff matrix. We conclude that both the decisions rules and the payoff matrix could affect how and when the equilibrium and the segregation emerge in the system. This is particularly interesting for the tag model, as it is related to the role of group recognition in economic decisions.

An Agent Based Model of the Nash Demand Game in Regular Lattices

In this work we propose an agent based model where a fixed finite population of tagged agents play iteratively the Nash demand game in a regular lattice. This work extends the multiagent bargaining model by [1] including the spatial dimension in the game. Each agent is endowed with memory and plays the best reply against the opponent’s most frequent demand. The results show that all the possible persistent regimes of the global interaction game can also be obtained with this spatial version. Our preliminary analysis also suggests that the topological distribution of the agents can generate new persistent regimes within groups of agents with the same tag.

Project Management Methodologies in the Fourth Technological Revolution

We are at the beginning of a new technological revolution, propelled by the development of cyber-physical systems and technologies like Internet of Things, Bid Data, Cloud Computing, 3D Printing, etc. Therefore, we will see an avalanche of projects to implement new business models, products, services and companies. In this paper, we analyse the main characteristics of these projects and we wonder about the appropriate methodologies and managerial styles to lead them. We argue that these projects are complex in nature, according to the current literature on project complexity and thus, classical project management approaches might be unsuitable for managing them. We suggest some clues to seek for new managerial styles, mainly in the literature concerning innovation and new product development and within the “Agile” approach.

Quality Uncertainty and Market Failure: An Interactive Model to Conduct Classroom Experiments

We present an interactive simulation game designed to teach the market effects of quality uncertainty. The instructor can conduct experiments in a virtual classroom, in which students using a computer are embedded in an online market playing the role of buyers. Many industrial engineering programs set aside these market effects because the impact of poor quality in customer behavior is very difficult to evaluate. This work complements traditional classroom approaches to quality improvement and standardization giving engineering students a clear justification for techniques to control and reduce variability in industrial and manufacturing processes. We propose a parameterization for a game and discuss the expected dynamics. Buyers with enough bad experiences form biased quality estimations and stop buying, which can make the market collapse. The game also allows exploring the influence of social networks as mechanism to enhance market performance. The game has been implemented in Netlogo and Hubnet platform.

Agent-Based Modelling and Archaeological Complexity

This paper presents a brief overview of social simulation in the field of Archaeology. It has been conducted from an agent-based modelling focus, a very interesting and valid methodology for modelling prehistoric societies. The second part of this work presents an application of this methodology in a specific model that analyses the emergence of ethnicity in a prehistoric society.