Modeling economic systems as locally-constructive sequential games

Real-world economies are open-ended dynamic systems consisting of heterogeneous interacting participants. Human participants are decision-makers who strategically take into account the past actions and potential future actions of other participants. All participants are forced to be locally constructive, meaning their actions at any given time must be based on their local states; and participant actions at any given time affect future local states. Taken together, these essential properties imply real-world economies are locally-constructive sequential games. This paper discusses a modeling approach, Agent-based Computational Economics, that permits researchers to study economic systems from this point of view. ACE modeling principles and objectives are first concisely presented and explained. The remainder of the paper then highlights challenging issues and edgier explorations that ACE researchers are currently pursuing

Learning optimization models in the presence of unknown relations

In a sequential auction with multiple bidding agents, it is highly challenging to determine the ordering of the items to sell in order to maximize the revenue due to the fact that the autonomy and private information of the agents heavily influence the outcome of the auction. The main contribution of this paper is two-fold. First, we demonstrate how to apply machine learning techniques to solve the optimal ordering problem in sequential auctions. We learn regression models from historical auctions, which are subsequently used to predict the expected value of orderings for new auctions. Given the learned models, we propose two types of optimization methods: a black-box best-first search approach, and a novel white-box approach that maps learned models to integer linear programs (ILP) which can then be solved by any ILP-solver. Although the studied auction design problem is hard, our proposed optimization methods obtain good orderings with high revenues. Our second main contribution is the insight that the internal structure of regression models can be efficiently evaluated inside an ILP solver for optimization purposes. To this end, we provide efficient encodings of regression trees and linear regression models as ILP constraints. This new way of using learned models for optimization is promising. As the experimental results show, it significantly outperforms the black-box best-first search in nearly all settings.Comment: 37 pages. Working pape

The Ambivalent Role of Mimetic Behaviors in Proximity Dynamics: Evidences on the French “Silicon Sentier”

This articles examines the peculiar role of mimetic behaviors in co-location processes. We start showing that geographical proximity between agents and/or firms is not a sufficient nor necessary condition for the collective performance of clusters. Other types of socio-economic proximities characterize clusters, and our purpose is to show that, among the several ways to analyze the complex links between proximities and clusters, the theoretical outlook on the role played by mimetic interactions in co-location processes are certainly one of the most promising. Mimetic behaviors of location (in economics and sociology) are introduced in order to demonstrate that co-location processes can be the result of sequentiality, uncertainty, legitimacy and non market interactions, rather than full rational and isolated decisions and pure strategic market interactions. According to the type of mimetic behavior at work in the clustering process, the nature of socio-economic proximity can differ and have a strong influence of the “evolutionary stability” of clusters. All these theoretical considerations are illustrated through the emblematic French case of “Silicon Sentier”, cluster which has gathered together three hundred firms of the French net-economy (the famous “dotcom”) during the Internet bubble swelling.cluster, mimetic interactions, proximity, stability, Silicon Sentier

Authority in the Context of Distributed Knowledge

The notion of distributed knowledge is increasingly often invoked in discussions of economic organization. In particular, the claim that authority is inefficient as a means of coordination in the context of distributed knowledge has become widespread. However, very little analysis has been dedicated to the relation between economic organization and distributed knowledge. In this paper, we concentrate on the role of authority as a coordination mechanism under conditions of distributed knowledge, and also briefly discuss other issues of economic organization. We clarify the meanings of authority and distributed knowledge, and criticize the above claim by arguing that authority may be a superior mechanism of coordination under distributed knowledge. We also discuss how distributed knowledge influences the boundaries of firms. Our arguments rely on insights in problem-solving and on ideas from organizational economics.Distributed knowledge, existence of authority, problem-solving, the boundaries of the firm

A Laboratory Experiment of Knowledge Diffusion Dynamics

This paper aims to study, by means of a laboratory experiment and a simulation model, some of the mechanisms which dominate the phenomenon of knowledge diffusion in the process that is called ‘interactive learning’. We examine how knowledge spreads in different networks in which agents interact by word of mouth. We define a regular network, a randomly generated network and a small world network structured as graphs consisting of agents (vertices) and connections (edges), situated on a wrapped grid forming a lattice. The target of the paper is to identify the key factors which affect the speed and the distribution of knowledge diffusion. We will show how these factors can be classified as follow: (1) learning strategies adopted by heterogeneous agents; (2) network architecture within which the interaction takes place; (3) geographical distribution of agents and their relative initial levels of knowledge. We shall also attempt to single out the relative effect of each of the above factors.Knowledge, Network, Small world, Experiment, Simulation.