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This paper provides a micro-foundation for dual market structure formation through partitioning processes in marketplaces by developing a computational model of interacting economic agents. We propose an agent-based modeling approach, where firms are adaptive and profit-seeking agents entering into and exiting from the market according to their (lack of) profitability. Our firms are characterized by large and small sunk costs, respectively. They locate their offerings along a unimodal demand distribution over a one-dimensional product variety, with the distribution peak constituting the center and the tails standing for the peripheries. We found that large firms may first advance toward the most abundant demand spot, the market center, and release peripheral positions as predicted by extant dual market explanations. However, we also observed that large firms may then move back toward the market fringes to reduce competitive niche overlap in the center, triggering nonlinear resource occupation behavior. Novel results indicate that resource release dynamics depend on firm-level adaptive capabilities, and that a minimum scale of production for low sunk cost firms is key to the formation of the dual structure.

The strategy of integration known as VMI (Vendor-Managed Inventory) allows the coordination of inventory policies between producers and buyers in supply chains. Based on a new proposed model for the implementation of VMI in a chain of two links composed of a producer and a buyer, this paper studies the evolution of individual strategies of the producer and the buyer by a formalism derived from the theory of evolutionary games. The conditions that determine the stability of evolutionarily stable strategies are derived and analyzed. Work results specify analytical conditions that favor the implementation of VMI on traditional chains without VMI.

This paper presents a multi-agent simulation that studies market competition in a multi-stage negotiation with both direct sales and intermediation, in the presence of cost heterogeneity at the agent (i.e., producer) level. Producers sell their products according to an adaptive reinforcement strategy. Product is sold to clients (small shops and consumers) according to two types of marketplaces, which are characterized by whether they obtain the product from intermediaries or directly from producers. The model is applied to the case of a networked market of potato (Solanum tuberosum) producers in Bogotá, Colombia, and calibrated to real data. The results reveal that, contingent upon the number of producers, number of intermediaries, unit transportation cost and producers' culture, intermediation might lead to greater traded quantities than sales through farmers' (local) markets. Also, we found that increasing the intensity of competition among intermediaries is at odds with the increase of producers' long run profit. Thus, we conclude that intermediation still plays an important role to maintain the supply ecosystem, especially when transportation costs are important in a network of isolated and fragmented network of producers.

This paper presents a multi-agent simulation that studies market based competition in a multi-stage negotiation with both direct sales and intermediation, in the presence of cost-related heterogeneity at the agent level. Producers sell their products according to an adaptive Q-learning strategy. Product is sold to clients (small shops and consumers) according to two types of marketplaces, which are characterized depending on whether they obtain the product from intermediaries or directly from producers. The model is inspired by a networked market of perishable goods in Bogotá, Colombia. The results show that, contingent upon unit transportation cost and producers’ learning rate, intermediation might lead to greater traded quantities than sales through direct marketplaces, although erosion of intermediaries’ profits might also become compromised. Thus, we conclude that intermediation could serve as a mechanism for increasing market efficiency.

We build an agent-based computational model to study how the changing number of active product variants in a two-dimensional product space affects the performance of different firm types (i.e. large-scale and small-scale enterprises). We use an alternative approach to measure product space dimensionality, considering that dimensions may be a fraction of the Euclidean measure. The results confirm that high dimensionality gives advantage to small-scale firms. Additionally, we find that large-scale firms may also benefit from initial increasing dimensionality, since it allows a small degree of product differentiation and price discrimination.

This paper demonstrates the application of two efficient cost allocation mechanisms on a simple FIFO network model in order to find congestion-based prices for network access services. It is shown that it is possible to obtain congestion-dependent prices in data networks (such as the Internet), establishing simultaneously different service quality levels among the users. The rationale behind these efficient distribution mechanisms is an axiomatic framework that determines a set of basic principles, highlighting the need for a fair allocation. Due to the characteristics of the price mechanisms and the possibilities of the parameter space in which these mechanisms might be applied, it is also shown that, in some cases, such mechanisms need additional weighting schemes in order to establish coherent differences among the service quality levels. In conclusion, even though the axiomatic framework guarantees efficient allocation, checking coherency in its use is left to the network manager.

The strategy of integration known as VMI (Vendor-Managed Inventory) allows the coordination of inventory policies between producers and buyers in supply chains. Based on a new proposed model for the implementation of VMI in a chain of two links composed of a producer and a buyer, this paper studies the evolution of individual strategies of the producer and the buyer by a formalism derived from the theory of evolutionary games. The conditions that determine the stability of evolutionarily stable strategies are derived and analyzed. Work results specify analytical conditions that favor the implementation of VMI on traditional chains without VMI.

Congestion effects are the negative externalities or social costs that users generate on each other when using a shared network resource. Under a congestion-based pricing scheme, networks with enough slack capacity should reflect a very low priced negative externality, while a network with reduced capacity to provide one more unit of the requested resource should reflect the negative effects in the form of higher prices for the use of network resources. This chapter deals with the efficient distribution of congestion costs among network users. First, we present a review of different approaches found in the literature, ranging from methods that advocate for congestion-based pricing to methods that, after being critical about considering congestion, advocate for price definition based on the investors' need for return on their investment. We then proceed to introduce an axiomatic approach to conges-IGI PUBLISHING

The strategy of integration known as vendor-managed inventory (VMI), which allows the coordination of inventory policies between producers and buyers in supply chains, has long been considered a strategy for inventory cost reduction. Although the literature acknowledges the importance of understanding the dynamics of VMI implementation through evolutionary games, research in this topic still remains scarce. This paper studies the dynamics of strategic interaction of a producer-buyer supply chain under a newly developed VMI scheme, which makes use of a synchronization mechanism between the buyer and the producer replenishment cycles. By using this alternative VMI representation, we obtain the mathematical conditions that determine the degree of stability of evolutionarily stable strategies. As other evolutionary game theoretical approaches, we also find a lower bound for penalty costs that ensures a VMI contract, but most importantly, we also find how a VMI implementation might depend on the difference between production and demand rates, regardless of any penalty costs.

Reflexive phenomena are usually understood in the social sciences as processes that a ect themselves recursively. This stems from the mutual altering relationship between participants and the social process they belong to: participants can change the course of the process with their actions and a new state during the evolution of the process can lead to a change in its participants' behavior. This article proposes an agent-based model of di usion of innovations in a social network to study reflexivity. In this model, agents decide to adopt a new product according to a utility function that depends on two kinds of social influences. First, there is a local influence exerted on an agent by her closest neighbors that have already adopted, and also by herself if she feels the product suits her personal needs. Second, there is a global influence which leads agents to adopt when they become aware of emerging trends happening in the system. For this, we endow agents with a reflexive capacity that allows them to recognize a trend, even if they can not perceive a significant change in their neighborhood. Results reveal the appearance of slowdown periods along the adoption rate curve, in contrast with the classic stylized bell-shaped behavior. Results also show that network structure plays an important role in the e ect of reflexivity: while some structures (e.g., scale-free networks) may amplify it, others (e.g., small-world structure) weaken such an e ect. The contribution of this work lies in the inclusion of evolving cognitive distinctions as agents decide product adoption in di usion processes.

Traditionally, firm competition has been studied in contexts where the dimensionality of the product attribute space is given, and firms deploy their strategies constrained by this space. However, firms may exert influence on the local structure of the product attribute space by offering product variants with new attributes. As a result, the geometry of the product attribute space would change endogenously through firms' actions, and this emergent new geometry modifies the conditions for subsequent firm behavior. By focusing on this interplay between actors and conditions, we explore the co-evolution of the firm and the product attribute space. Through a multi-variant Cournot competition framework, we develop a computational model in which firms invest to differentiate their products from other variants, but as minimally as possible so that demand from closely similar existing variants can be stolen. We introduce the fraction dimensionality of the attribute space as our critical independent variable, to reflect saturation of the space with product varieties. The simulation reveals that while new product variants are typically introduced by firms with scale economies, their performance gap with firms without scale economies reduces as fraction dimensionality increases. This indicates that space geometry evolution may favor small-scale players, even when their large-scale competitors are the driving force behind attribute space changes. 1 Introduction: Commodity space evolution Attribute spaces display how demand for, and supply of, organizational services distributes over a number of attributes, or dimensions, that characterize the offerings [1]. As the number of product attributes taken into account by economic actors is a natural number, we straightforwardly associate the complexity of the attribute space with its positive integer dimensionality. The attribute space can be a commodity space spun by product characteristics that prospective customers evaluate [1, 2, 3], a market place that combines product design and product quality features [4], or a political issue space within which political representation is offered [5, 6]. In organization science, this can be a Blau-space [7] dimensioned by people's

We built a computational model of political party competition in order to gain insight into the effect of the decrease in the number of relevant political issues (dimensions), and the change of their relative importance, on the number of surviving political parties, their strategy performance, and the degree of political party fragmentation. Particularly, we find that when there is a dimensionality reduction (i.e., a change from a two-dimensional issue space to a one-dimensional one, or, a substantial decrement in one of the issue's relative importance with respect to the other), the number of political parties declines, as does the overall degree of party fragmentation in the system. Regarding party strategies, we observe that, after the dimensionality reduction, (i) the inert parties tend to improve their performance in terms of party numbers (i.e., more inert parties survive, relatively * Corresponding author.

Economics and engineering are discovering new opportunities for cross-fertilization. This is partly given to the advent of modern artificial intelligence methods. These opportunities have appeared in the past, resulting in marginal improvements toward integration. As explained by Mariotti (Journal of Industrial and Business Economics, 2021), over the years there has been an intertwining of the two disciplines along the progression of economics for/and/as engineering. Mariotti (2021) also points out that a real transdisciplinary integration (i.e., à la Prigogine) implies a mutual nurturing, where one discipline´s conceptual apparatus is incorporated into the other. A fine-grained view of the epistemological differences of the two disciplines reveals that an integration might be more likely along some, but not all directions. I explain these differences based on different connotations of the concept of design. Particularly, when referring to design aspects of social systems, I also argue that systems approaches may serve as a bridge to integrate economics and engineering. Finally, I offer alternatives to explore how this integration might be undertaken.

Hundreds of thousands of tons of food are either lost or wasted while millions of people suffer from malnutrition. A plausible initiative are the food banks in which large retail chains and potentially other organizations can donate food. This food is collected and delivered by food banks to people in need. Such food banks have helped thousands of people but still the percentages are negligible as compared to the large quantities of food that are wasted with no more reason that destroying is cheaper. On the other hand, food banks have also their own problems: Poor distribution strategies, informality in handling and delivering food, lack of infrastructure, the mismatch between the supply and nutrition needs, among others. As consequence, research and actions are needed to improve the efficiency of food banks.

We develop an agent-based computational model in which the urban informal sector acts as a buffer where rural migrants can earn some income while queuing for higher paying modern-sector jobs. In the model, the informal sector emerges as a result of rural-urban migration decisions of heterogeneous agents subject to social influence in the form of neighboring effects of varying strengths. Besides using a multinomial logit choice model that allows for agent idiosyncrasy, explicit agent heterogeneity is introduced in the form of socio-demographic characteristics preferred by modern-sector employers. We find that different combinations of the strength of social influence and the socioeconomic composition of the workforce lead to very different urbanization and urban informal sector shares. In particular, moderate levels of social influence and a large proportion of rural inhabitants with preferred socio-demographic characteristics are conducive to a higher urbanization rate and a larger informal sector.

The strategy of integration known as VMI (Vendor-Managed Inventory) allows the coordination of inventory policies between producers and buyers in supply chains. Based on a new proposed model for the implementation of VMI in a chain of two links composed of a producer and a buyer, this paper studies the evolution of individual strategies of the producer and the buyer by a formalism derived from the theory of evolutionary games. The conditions that determine the stability of evolutionarily stable strategies are derived and analyzed. Work results specify analytical conditions that favor the implementation of VMI on traditional chains without VMI.