Roles of mutation rate and co-existence of multiple strategy updating rules in evolutionary prisoner's dilemma games

The emergence and maintenance of cooperation has attracted intensive scholarly interest and has been analysed within the framework of evolutionary game theory. The role of innovation, which introduces novel strategies into the population, is a relatively understudied aspect of evolutionary game theory. Here, we investigate the effects of two sources of innovation---mutation and heterogeneous updating rules. These mechanisms allow agents to adopt strategies that do not rely on the imitation of other individuals. The model introduces---in addition to canonical imitation-based strategy updating---aspiration-based updating, whereby agents switch their strategy by referring solely to the performance of their own strategy; mutation also introduces novel strategies into the population. Our simulation results show that the introduction of aspiration-based rules into a population of imitators leads to the deterioration of cooperation. In addition, mutation, in combination with heterogeneous updating rules, also diminishes cooperators. This phenomenon is prominent when a large proportion of the population consists of imitators rather than adopters of aspiration-based updating. Nevertheless, a high mutation rate, in combination with a low aspiration level, has positive nonlinear effects, and a heterogeneous population achieves a higher level of cooperation than the weighted average of homogeneous populations. Our results demonstrate the profound role of innovation in the evolution of cooperation.Comment: 7 pages, 8 figures, Figs 3(b) and 8 were added following the reviewers' comment

An evolutionary game model for behavioral gambit of loyalists: Global awareness and risk-aversion

We study the phase diagram of a minority game where three classes of agents are present. Two types of agents play a risk-loving game that we model by the standard Snowdrift Game. The behaviour of the third type of agents is coded by {\em indifference} w.r.t. the game at all: their dynamics is designed to account for risk-aversion as an innovative behavioral gambit. From this point of view, the choice of this solitary strategy is enhanced when innovation starts, while is depressed when it becomes the majority option. This implies that the payoff matrix of the game becomes dependent on the global awareness of the agents measured by the relevance of the population of the indifferent players. The resulting dynamics is non-trivial with different kinds of phase transition depending on a few model parameters. The phase diagram is studied on regular as well as complex networks

Innovation Networks in the Biotechnology-Based Sectors

Technological progress in the biological sciences is now advancing across such a wide range and at such a pace, that, irrespective of size, no firm can hope to keep up in all the different areas. Participating in innovation networks, bundling of competencies and capabilities, therefore, offers an alternative to extremely expensive go-it-alone strategies, whether carried out by acquisition and mergers or by isolated R&D. This imbalance between the rate of growth of the biotechnology knowledge base and the capability of individual firms to access it can explain the persistence of cooperative R&D in the biotechnology-based sectors at the end of the 90s. Such imbalance is not due any more only to the lack of absorptive capacity of existing firms, because the large pharmaceutical firms have meanwhile developed considerable competencies in that field. This previous competence-gap was considered to be the reason for cooperative behaviour in the early phases of these industries in the end of the 70s and early 80s. To the extent that this was considered to be the only knowledge gap innovation networks were considered as a temporary phenomenon, which could not persist beyond the period required by large firms to catch up with the new technology. We are then proposing that a new role, that of explorers scanning parts of the knowledge space that LDFs (Large Diversified Firms) are capable of exploring but unwilling to commit themselves in an irreversible way, can be played by DBFs (Dedicated Biotechnology Firms) in innovation networks. Our simulation approach attempts to represent the emergence of these two roles as endogenous changes in the motivation for participating in innovation networks, allowing them to become an important and long-lasting organizational device for industrial R&D. Drawing on a history friendly modeling approach the decisive mechanisms responsible for the emergence of innovation networks in these industries are figured out and compared to real developments.entrepreneurship, human capital, venture capital, social networks, evolutionary economics, swarms of innovations

Boundaryless Management - Creating, transforming and using knowledge in inter-organizational collaboration. A literature review

Current literature on organizations often argues that firms are becoming increasingly dependent on knowledge residing outside their own boundaries requiring organizations to increase their entrepreneurial abilities and make their boundaries more flexible and permeable. This paper reviews the literature on what might be called interorganizational knowledge work. Implied in this focus is an assumption of clear organizaitonal boundaries. Rather than taking these boundaries and their importance for granted, the current review, however, aims at relativizing these boundaries. By focusing the empirical phenomenon of collaboration between individuals in different organizations, four different streams of literature with different constructions of the organizational boundary and its importance were identified: the literature on learning in alliances and joint ventures, the literature on collaboration in industrial networks, the literature on social networks and communities of practice and finally the literature on geographical clusters and innovation systems. The above four streams of the literature are reviewed with a special focus on the following three questions: 1. What is the role of (organizational) boundaries in interorganizational knowledge work? 2. What do we know about how these boundaries can be overcome? 3. What are the implications for managing interorganizational knowledge work spelled out in the literature?Interorganizational collaboration; Knowledge Management; Literature review

Making the city of commons: popular economies between urban conflicts and capitalistic accumulation

A partire da una ricerca etnografica, in questo articolo analizzo i processi di produzione dell'urbano attraverso pratiche di commoning e processi di autorganizzazione in due differenti esperienze cooperative nell'area metropolitana di Buenos Aires. Analizzando le relazioni tra accumulazione capitalistica, trasformazioni del lavoro e produzione dello spazio urbano, e sviluppando una critica della categoria di informalità, l'obiettivo è presentare le economie popolari come campo ambivalente di conflitto, soggettivazione e possibilità di trasformazione sociale. Ricostruendo i processi socio-spaziali nell'esperienza della cooperativa Juana Villca e della fabbrica recuperata "19 de Diciembre", il contributo riflette sulle ambivalenze, potenzialità e sfide delle esperienze di autogestione del lavoro in quanto infrastrutture di una emergente istituzionalità popolare dal basso.Based on an ethnographic research, this article analyzes the urban making from below through commoning and self organization social processes in two different cooperative experiences in the metropolitan area of Buenos Aires. By analyzing the relationships between capitalistic accumulation, labour transformation and the production of urban spaces, and developing a critique of the category of informality, the aim is presenting popular economies as an ambivalent field of conflict, subjectivation and social transformation possibilities. Delineating the socio-spatial processes in the experiences of Juana Villca cooperative and recuperated enterprise "19 de Diciembre", the contribution reflects on ambivalences, potentialities and challenges of self managed labour experiences as infrastructure of an emergent popular institutionality from below

Optimal distribution of incentives for public cooperation in heterogeneous interaction environments

In the framework of evolutionary games with institutional reciprocity, limited incentives are at disposal for rewarding cooperators and punishing defectors. In the simplest case, it can be assumed that, depending on their strategies, all players receive equal incentives from the common pool. The question arises, however, what is the optimal distribution of institutional incentives? How should we best reward and punish individuals for cooperation to thrive? We study this problem for the public goods game on a scale-free network. We show that if the synergetic effects of group interactions are weak, the level of cooperation in the population can be maximized simply by adopting the simplest "equal distribution" scheme. If synergetic effects are strong, however, it is best to reward high-degree nodes more than low-degree nodes. These distribution schemes for institutional rewards are independent of payoff normalization. For institutional punishment, however, the same optimization problem is more complex, and its solution depends on whether absolute or degree-normalized payoffs are used. We find that degree-normalized payoffs require high-degree nodes be punished more lenient than low-degree nodes. Conversely, if absolute payoffs count, then high-degree nodes should be punished stronger than low-degree nodes.Comment: 19 pages, 8 figures; accepted for publication in Frontiers in Behavioral Neuroscienc

Social dilemmas in an online social network: the structure and evolution of cooperation

We investigate two paradigms for studying the evolution of cooperation--Prisoner's Dilemma and Snowdrift game in an online friendship network obtained from a social networking site. We demonstrate that such social network has small-world property and degree distribution has a power-law tail. Besides, it has hierarchical organizations and exhibits disassortative mixing pattern. We study the evolutionary version of the two types of games on it. It is found that enhancement and sustainment of cooperative behaviors are attributable to the underlying network topological organization. It is also shown that cooperators can survive when confronted with the invasion of defectors throughout the entire ranges of parameters of both games. The evolution of cooperation on empirical networks is influenced by various network effects in a combined manner, compared with that on model networks. Our results can help understand the cooperative behaviors in human groups and society.Comment: 14 pages, 7 figure