Coevolution of economic and ecological systems

This paper analyzes a model of economy–environment coevolution in which economic activities induce the genetic evolution of a biological species. This model is applied to the problem of pesticide resistance management. Just as in Munro (Environ Resour Econ, 9:429–449, 1997), we consider three main types of interactions: (1) a large pest population reduces economic revenues, (2) economic activities select for resistant genes and (3) the spread of resistant genes affects the size of the pest population. The model differs from Munro in that it includes evolutionary modeling of economic strategies. Economic agents are assumed to be boundedly rational, i.e they cannot compute the optimal level of pesticide use that minimizes resistance among pests. Economic evolution represents the change in the distribution of pesticide strategies in the population of economic agents and is modeled by a replicator dynamics equation. The interactions between economic evolution of pesticide strategies, pest population dynamics and genetic evolution of resistance of pests are studied in a system of three differential equations. We explore the dynamics and stability properties of the system using numerical simulations.     

Stochastic strategy adjustment in coordination games

Summary. The paper explores a model of equilibrium selection in coordination games, where agents from an infinite population stochastically adjust their strategies to changes in their local environment. Instead of playing perturbed best-response, it is assumed that agents follow a rule of ‘switching to better strategies with higher probability’. This behavioral rule is related to bounded-rationality models of Rosenthal (1989) and Schlag (1998). Moreover, agents stay with their strategy in case they successfully coordinate with their local neighbors. Our main results show that both strict Nash equilibria of the coordination game correspond to invariant distributions of the process, hence evolution of play is not ergodic but instead depends on initial conditions. However, coordination on the risk-dominant equilibrium occurs with probability one whenever the initial fraction contains infinitely many agents, independent of the spatial distribution of these agents. Received: March 14, 2000; revised version: June 21, 2001     

What constitutes a convention? Implications for the coexistence of conventions

A model of repeated play of a coordination game, in which stage games have a location in social space and players receive noisy signals of the true location of their games, is reviewed. Sugden (1995) (The coexistence of conventions. J Econ Behav Organ 28:241–256) suggests that, in such a model, there can be a stationary state of convention coexistence only if interaction is non-uniform across social space. This paper shows that an alternative definition of conventions, which links conventions to actions rather than expectations, permits convention coexistence when interaction is uniform. To assess robustness, the concept of a global mutant is introduced, to which certain states of coexistence are robust.

Maritime trade and migratory species management to protect biodiversity

Invasive species threaten biodiversity worldwide. Ships inadvertently carry marine invasive species to vulnerable ports. An empirical game theoretic analysis is presented to explore this transboundary biological pollution topic. This analysis utilizes data on marine invasive species and maritime trade as a vector of impact on native species at different public port locations along the Pacific coast of the North American countries. Preventative and reactive abatement strategies are compared. The countries are not identical and a comparison of noncooperative game strategies and payoffs to the cooperative game is presented. With the asymmetry between countries, optimal sharing rules are quantified. Results show that cooperative and preventative abatement is optimal compared to all other strategies dealing with stock and flow pollution.      

Competition and coordination in experimental minority games

This work presents experimental results on a coordination game in which agents must repeatedly choose between two sides, and a positive fixed payoff is assigned only to agents who pick the minoritarian side. We conduct laboratory experiments in which stationary groups of five players play the game for 100 periods, and manipulate two treatment variables: the amount of information about other players’ past choices and the salience of information regarding the game history (i.e., the length of the string of past outcomes that players can see on the screen while choosing). Our main findings can be summarized as follows: aggregate efficiency in the game is in most cases significantly higher than the level corresponding to the symmetric mixed strategy Nash equilibrium. In addition, providing players with information about individual choices in the group does not improve aggregate efficiency with respect to when such information is absent. Displaying information about more rounds than just the previous one, on the other hand, seems to have a positive effect on aggregate efficiency. At the individual level, we find a stronger statistical relation between players’ current choices and their own past choices than between players’ choices and previous aggregate outcomes. In addition, the depth of the relation between present and past choices seems to be affected by the prompt availability of information about the game history. Finally, we detect evidence of a mutual co-adaptation between players’ choices over time that is partly responsible for the high level of efficiency observed.      

International duopoly with overseas production and strategic trade policies

This paper examines the strategic export policies in a reciprocal market model of an international Cournot duopoly where two firms in domestic and foreign countries reciprocally supply their products to other countries through overseas production as well as export. It also considers the fact that the firms must incur export costs in addition to production costs. Thus, this paper shows, among others, that the effects of export policies on firms' output and export choices do not depend on the slopes of firms' reaction curves. It is also shown that firms' total outputs are independent of the export policies, and the optimal domestic and foreign export subsidies are zero (laissez-faire).     

Contracts and externalities: How things fall apart

A single principal interacts with several agents, offering them contracts. The crucial assumption of this paper is that the outside-option payoffs of the agents depend positively on how many uncontracted or “free” agents there are. We study how such a principal, unwelcome though he may be, approaches the problem of contract provision to agents when coordination failure among the latter group is explicitly ruled out. Two variants are considered. When the principal cannot re-approach agents, there is a unique equilibrium, in which contract provision is split up into two phases. In phase 1, simultaneous offers at good (though varying) terms are made to a number of agents. In phase 2, offers must be made sequentially, and their values are “discontinuously” lower: they are close to the very lowest of all the outside options. When the principal can repeatedly approach the same agent, there is a multiplicity of equilibria. In some of these, the agents have the power to force delay. They can hold off the principal's overtures temporarily, but they must succumb in finite time. In both models, despite being able to coordinate their actions, agents cannot resist an “invasion” by the principal and hold to their best payoff. It is in this sense that “things [eventually] fall apart”.     

Cooperation and cultural transmission in a coordination game

The aim of this paper is to analyze if cooperation can be the product of cultural evolution in a two-stage coordination game, consisting of a production stage followed by a negotiation phase. We present an overlapping generations model with cultural transmission of preferences where the distribution of preferences in the population and the strategies are determined endogenously and simultaneously. There are several groups in the society; some of them play cooperatively and others do not. Socialization takes place inside the group, but there is a positive rate of migration among groups which parents anticipate. Our main result shows that all groups converge to the cooperative equilibrium.     

Social learning in coordination games: does status matter?

We report the results of experiments designed to test the impact of social status on learning in a coordination game. In the experiment, all subjects observe the play of an agent who either has high status or low status. In one treatment the agent is another player in the game; in the other the agent is a simulated player. Status is assigned within the experiment based on answers to a trivia quiz. The coordination game has two equilibria: one is payoff-dominant but risky, and the other is risk-dominant. The latter is most commonly chosen in experiments where there is no coordination device. We find that a commonly observed agent enhances coordination on the payoff-dominant equilibrium more often when the agent has high status.      

Experimental evidence on the ‘insidious’ illiquidity risk

This paper introduces an experiment aiming to investigate the contribution of illiquidity risk to the total risk of a collective investment project. If implemented, the project succeeds with a known probability. Yet the project fails if the quota of investors is not reached in the first place. Hence strategic uncertainty compounds its effect with the “intrinsic risk” of the project. Results confirm the insidious nature of illiquidity: as long as a first collective default does not occur, investors accept high intrinsic risk projects. After a first default, they become extremely prudent and come back to market only gradually. After several defaults, private agents manage to coordinate on a relatively low intrinsic risk above which they refuse to participate in the project. Macroeconomic policy implications follow.     

The governance of innovative firms: An evolutionary perspective

Corporate governance has been in the recent years one of the most debated issues in conventional economic approaches. Agency theory combined with financial indicators has particularly contributed to the development of shareholder value as a key concept in companies’ governance both at a theoretical and empirical level. We argue that an evolutionary perspective can be developed on the governance of innovative firms since (1) conventional economic approaches only consider a restricted part of this complex issue, and (2) this restricted vision applied in practice has driven the economic system into major coordination problems and turbulences. On the basis of empirical investigations into the telecommunications industry, and guided by a simple model of evolutionary game, we propose new principles of corporate governance centered upon managerial entrepreneurship and its role on innovation and industry dynamics. The outcome is a set of rules of conduct for the manager and the shareholder.     

Coordination,timing and common knowledge

There is tight link between coordination and common knowledge. The role of higher order beliefs in static incomplete information games has been widely studied. In particular, information frictions break down common knowledge. A large body of literature in economics examine dynamic coordination problems when there are timing frictions, in the sense that players do not all move at once. Timing frictions in dynamic coordination games play a role that is closely analogous to information frictions in static coordination games.This paper makes explicit the role of higher order beliefs about timing in dynamic coordination games with timing frictions. An event is said to be effectively known if a player knew the event when he last had an option to change his behavior. The lack of effective common knowledge of the time drives results of dynamic coordination games.     

Puzzles in the economic institutions of capitalism: production coordination, contracting and work organisation in the Irish linen trade, 1750-1850

Pre-Famine Ireland is a byword for market failure and path dependence.Production of flax yarn and linen cloth was highly regulatedand coordinated by the market rather than by firms. Contemporarypolitical economists suggested that these institutional featuresprovided evidence of organisational inefficiency. The historicalevidence suggests that they were a rational response to transactionand production costs. The Irish case provides a test of thehypotheses that firms emerge to reduce the cost of market transactions.It suggests that institutions other than the firm can modifytransaction costs, coordination of production can affect bothtransaction and production costs, and that agents choose betweenmarket and firm coordination given technology and factor prices.Finally, centralisation of production was driven by technology.     

Adaptive play with spatial sampling

We consider a 2×2 coordination game where each agent interacts with his neighbors on a ring. Ellison (1993, Econometrica 61, 1047–1071) shows that the discrete dynamical system generated by the myopic best-reply rule converges to a Nash equilibrium or to a two-period limit cycle. Following Young (1993, Econometrica 61, 57–84), we consider a best-reply process with a sampling procedure. Particularly, we introduce a spatial sampling procedure: each agent observes a sample of information in his neighborhood and plays a best reply to it. We show that if the size of the sample of information is not too large, the best-reply process converges almost surely to a Nash equilibrium. If in addition agents experiment with small probabilities, we show that, in most cases, the risk-dominant equilibrium prevails in the long run. Furthermore, it turns out that the convergence is faster than in Ellison.     

It takes two to cheat: An experiment on derived trust

Social life offers innumerable instances in which trust decisions involve multiple agents. Of particular interest is the case when a breach of trust is not profitable if carried out in isolation, but requires an agreement among agents. In such situations the pattern of behaviors is richer than in dyadic games, because even opportunistic trustees who would breach trust when alone may act trustworthily based on what they believe to be the predominant course of action. Anticipating this, trusters may be more inclined to trust. We dub these motivations derived trustworthiness and derived trust. To capture them, we design a “Collective Trust Game” and study it by means of a laboratory experiment. We report that overall levels of trustworthiness are almost thirty percentage points higher when derived motivations are present, and this generates also higher levels of trust. In our set-up, the effects of derived trustworthiness are comparable in size to positive reciprocity, and more important than concerns for equality.     

Coevolution of product quality and consumer preferences

This paper seeks to analyze the self-reinforcing coevolutionary process of innovation on the basis of the framework of evolutionary ecology and population genetics. Particularly central to this analysis is “Fisher’s runaway process,” which explains the coevolution of product quality and consumer preference in the supply–demand context. This paper puts forward the following main points. First, we can conclude from a matching model of supply and demand that when a consumer who prefers high-quality products discovers such a product in the market, he/she will certainly purchase that product. Second, taking into account both the high survival rate of a firm that supplies a high-quality product and the cost incurred by the firm in improving product quality, we arrive at an evolutionarily stable Fisher’s process. The third point, however, considers the disutility of a consumer with an inordinately high quality preference; in this case, Fisher’s process disappears. Fourth, it is possible to recover Fisher’s process if we consider the existence of power users or the effect of the negative bias of innovation.     

Sanctions that signal: An experiment

The introduction of sanctions provides incentives for more pro-social behavior, but may also be a signal that non-cooperation is prevalent. In an experimental minimum-effort coordination game we investigate the effects of the information contained in the choice to sanction. We compare the effect of sanctions that are introduced exogenously by the experimenter to that of sanctions which have been actively chosen by a subject who has superior information about the previous effort of the other players. We find that cooperative subjects perceive actively chosen sanctions as a negative signal which significantly reduces the effect of sanctions.     

Long-term impact of trade liberalization on human capital formation

While a growing line of research has assessed the effect of trade liberalization on human capital formation, most of these studies focus on its short-term effect on individual’s school attendance. Much less is known about its long-run effect, as well as the impact on other aspects of human capital formation such as labor market and noncognitive outcomes. This paper studies the impact of trade liberalization on individuals’ long-term human capital accumulation, including school attendance, cognitive abilities, labor market performance, and noncognitive outcomes. By constructing prefecture-year-level tariff barriers, our identification strategy exploits variations in different cohorts’ exposure to a trade shock at age 16 for individuals within the same prefecture. Empirical results suggest that trade liberalization leads to decreased completed years of schooling, cognitive abilities, wage, and noncognitive outcomes. We provide suggestive evidence that this observed pattern is explained by the expansion of job opportunities in relatively low-skilled and labor-intensive sectors.     

Paradoxical trade patterns and terms of trade

It is shown that, when a monopoly is present in a two-country, two-commodity world, the terms-of-trade do not necessarily fall in between the pre-trade relative prices of the two countries, and that these pre-trade prices do not unequivocally determine the pattern of trade.