SABIIA - Sistema Aberto e Integrado de Informação em Agricultura (Sabiia)

McFadzean, David; Tesfatsion, Leigh.

This paper presents a general C++ platform for the implementation of a trade network game (TNG) that combines evolutionary game play with preferential partner selection. In the TNG, successive generations of resource constrained traders choose and refuse trade partners on the basis of continually updated expected payoffs, engage in risky trades modelled as two-person games, and evolve their trade strategies over time. The modular design of the TNG platform facilitates experimentation with alternative specifications for market structure, trade partner matching, trading, expectation formation, and trade strategy evolution. The TNG platform can be used to study the evolutionary implications of these specifications at three different levels: individual...

NON-EMPLOYMENT BENEFITS AND THE EVOLUTION OF WORKER-EMPLOYER COOPERATION: EXPERIMENTS WITH REAL AND COMPUTATIONAL AGENTS

Palavras-chave: C++ platform; Trade networks; Evolutionary game; Partner matching; Endogenous interactions; Agent-based computational economics; Artificial life; International Relations/Trade.

Ano: 1996

URL: http://purl.umn.edu/18192

Pingle, Mark; Tesfatsion, Leigh.

Experiments with real and computational agents are used to examine the impact of changing the level of a non-employment payoff on the evolution of cooperation between workers and employers participating in a sequential employment game with incomplete contracts. Workers either direct work offers to preferred employers or choose unemployment and receive the non-employment payoff. Subject to capacity limitations, employers either accept work offers from preferred workers or remain vacant and receive the non-employment payoff. Matched workers and employers participate in an employment relationship modeled as a prisoner's dilemma game. In both types of experiments, increases in the non-employment payoff result in higher unemployment and vacancy rates while...

EX ANTE CAPACITY EFFECTS IN EVOLUTIONARY LABOR MARKETS WITH ADAPTIVE SEARCH

Palavras-chave: Labor and Human Capital.

Ano: 2001

URL: http://purl.umn.edu/18190

For a postscript copy of this paper, click <a href="/Data/isu/er48.ps"> here. </A> This study reports on computational experiments for an agent-based labor market model with adaptive choice and refusal of worksite partners and with endogenously evolving worksite behaviors. Two treatment factors are experimentally varied: market structure; and ex ante capacity constraints on potential work offers and job openings. Particular attention is focused on experimentally determined correlations between treatment factors and the formation of contractual networks among workers and employers, and between contractual network formation and the types of worksite interactions and welfare outcomes that these contractual networks support.

HYSTERESIS IN AN EVOLUTIONARY LABOR MARKET WITH ADAPTIVE SEARCH

Palavras-chave: Labor markets; Search and matching; Contractual networks; Adaptation; Evolutionary game; Agent-based computational economics; C++ source code; Labor and Human Capital.

Ano: 1998

URL: http://purl.umn.edu/18198

This study undertakes a systematic experimental investigation of hysteresis (path dependency) in an agent-based computational labor market framework. It is shown that capacity asymmetries between work suppliers and employers can result in two distinct hysteresis effects, network and behavioral, when work suppliers and employers interact strategically and evolve their worksite behaviors over time. These hysteresis effects result in persistent heterogeneity in earnings and employment histories across agents who have no observable structural differences. At a more global level, these hysteresis effects are shown to result in a one-to-many mapping between treatment factors and experimental outcomes. These hysteresis effects may help to explain why excess...

A TRADE NETWORK GAME WITH ENDOGENOUS PARTNER SELECTION

Palavras-chave: Labor markets; Network hysteresis; Behavioral hysteresis; Capacity asymmetries; Agent-based computational economics; Labor and Human Capital.

Ano: 1999

URL: http://purl.umn.edu/18189

This paper develops a Trade Network Game (TNG) that combines evolutionary game play with endogenous partner selection. Resource-constrained buyers and sellers choose and refuse trade partners on the basis of continually updated expected payoffs. Partner selection takes place in accordance with a "deferred choice and refusal" mechanism that is shown to have interesting stability, optimality, and uniqueness properties. The iterated prisoner's dilemma strategies used by buyers and sellers to conduct their trades are evolved over time via a genetic algorithm that biases reproduction in favor of strategies that have been successful in past trades. The TNG is shown to encompass a variety of economic applications, such as job search games, labor markets...

HOW ECONOMISTS CAN GET ALIFE

Palavras-chave: Trade networks; Evolutionary game; Optimal search; Endogenous interactions; Iterated prisoner's dilemma; Multi-armed bandit game; Assignment game; Preferential partner matching; Genetic algorithm; Artificial life; Criterion filtering; International Relations/Trade.

Ano: 1995

URL: http://purl.umn.edu/18191

This paper presents a summary overview of the fast-developing field of "artificial life," stressing aspects that seem especially relevant for the study of decentralized market economies. In particular, recent artificial life work combining evolutionary game theory with preferential partner selection is described in some detail. This work is currently being applied to the endogenous formation and evolution of trade networks.

A COMPUTATIONAL LABORATORY FOR EVOLUTIONARY TRADE NETWORKS

Palavras-chave: Institutional and Behavioral Economics.

Ano: 1995

URL: http://purl.umn.edu/18196

Tesfatsion, Leigh; Stewart, Deron; McFadzean, David.

This study presents, motivates, and illustrates the use of a computational laboratory for the investigation of evolutionary trade network formation among strategically interacting buyers, sellers, and dealers. The computational laboratory, referred to as the Trade Network Game Laboratory (TNG Lab), is targetted for the Microsoft Windows desktop. The TNG Lab is both modular and extensible and has a clear, easily operated graphical use interface. It permits visualization of the formation and evolution of trade networks by means of real-time animations. Data tables and charts reporting descriptive performance statistics are also provided in real time. The capabilities of the TNG Lab are demonstrated by means of labor market experiments.

TEACHING AGENT-BASED COMPUTATIONAL ECONOMICS TO GRADUATE STUDENTS

Palavras-chave: Computational laboratory; Buyer-seller trade networks; Evolutionary game; Network animation; Agent-based computational economics; C++ class framework; Labor market experiments; International Relations/Trade.

Ano: 2000

URL: http://purl.umn.edu/18199

For a postscript copy of this paper, click <a href="/Data/isu/er45.ps"> here. </A> Agent-base computational economics (ACE) is roughly defined as the computational study of economies modelled as evolving decentralized systems of autonomous interacting agents. A key focus of ACE research is understanding how global regularities arise from the bottom up, through the repeated local interactions of autonomous agents channeled through socio-economic institutions, rather than from top down coordination mechanisms such as imposed market clearing constraints or an assumption of single representative agents. This paper discusses how ACE materials have been introduced into graduate-level course in macroeconomic theory over the past several years,...

MARKET POWER AND EFFICIENCY IN A COMPUTATIONAL ELECTRICITY MARKET WITH DISCRIMINATORY DOUBLE-AUCTION PRICING

Palavras-chave: Institutional and Behavioral Economics; Teaching/Communication/Extension/Profession.

Ano: 1998

URL: http://purl.umn.edu/18193

Tesfatsion, Leigh; Petrov, Valentin; Nicolaisen, James.

This study reports experimental market power and efficiency outcomes for a computational wholesale electricity market operating in the short run under systematically varied concentration and capacity conditions. The pricing of electricity is determined by means of a clearinghouse double auction with discriminatory midpoint pricing. Buyers and sellers use a modified Roth Erev individual reinforcement learning algorithm to determine their price and quantity offers in each auction round. It is shown that high market efficiency is generally attained, and that market microstructure is strongly predictive for the relative market power of buyers and sellers independently of the values set for the reinforcement learning parameters. Results are briefly compared...

STRUCTURE, BEHAVIOR, AND MARKET POWER IN AN EVOLUTIONARY LABOR MARKET WITH ADAPTIVE SEARCH

Palavras-chave: Wholesale electricity market; Restructuring; Repeated double auction; Market power; Efficiency; Concentration; Capacity; Individual reinforcement learning; Genetic algorithm social learning; Agent-based computational economics; Industrial Organization.

Ano: 2001

URL: http://purl.umn.edu/18195

This study uses an agent-based computational labor market framework to undertake a systematic experimental investigation of the relationship between job capacity, job concentration, and market power. Job capacity is measured by the ratio of total potential job openings to total potential work offers, and job concentration is measured by the ratio of work suppliers to employers. For each setting of the capacity and concentration treatment factors, work suppliers and employers repeatedly seek preferred worksite partners based on continually updated expected utility, engage in efficiency-wage worksite interactions modelled as prisoner's dilemma games, and evolve their worksite behaviors over time. The main finding is that job capacity consistently trumps...

GALE-SHAPLEY MATCHING IN AN EVOLUTIONARY TRADE NETWORK GAME

Palavras-chave: Labor market dynamics; Market power; Job capacity; Job concentration; Adaptive search; Networks; Endogenous interactions; Agent-based computational economics; Evolutionary game; Labor and Human Capital.

Ano: 1999

URL: http://purl.umn.edu/18197

For a postscript copy of this paper, click <a href="/Data/isu/er43.ps"> here. </A> This study investigates the performance of Gale-Shapley matching in an evolutionary market context. Computational experimental findings are reported for an evolutionary match-and-play trade network game in which resource-constrained traders repeatedly choose and refuse trade partners in accordance with Gale-Shapley matching, participate in risky trades modelled as two-person prisoner's dilemma games, and evolve their trade behavior over time. Particular attention is focused on correlations between ex ante market structure and the formation of trade networks, and between trade network formation and the types of trade behavior and social welfare outcomes that...

AN EVOLUTIONARY TRADE NETWORK GAME WITH PREFERENTIAL PARTNER SELECTION

Palavras-chave: Evolutionary game; Gale-Shapley matching; Iterated prisoners' dilemma; Trade networks; Endogenous interactions; Agent-based computational economics; International Relations/Trade; C7; C8; C9; D8; D4.

Ano: 1998

URL: http://purl.umn.edu/18200

An evolutionary trade network game (TNG) is proposed for studying the interplay between evolutionary game dynamics and preferential partner selection in various market contexts with distributed adaptive agents. The modular form of the TNG facilitates experimentation with alternative specifications for trade partner matching, trading, expectation up dating, and trade strategy evolution. Experimental results obtained using a C++ implementation suggest that the conventional optimality properties used to evaluate agent matching mechanisms in static market contexts maybe inadequate measures of optimality from an evolutionary perspective.

DC Optimal Power Flow Formulation and Solution Using QuadProgJ

Palavras-chave: International Relations/Trade.

Ano: 1996

URL: http://purl.umn.edu/18188

Sun, Junjie; Tesfatsion, Leigh.

Replaced with revised version of paper 06/21/06.