Promotion of cooperation induced by the interplay between structure and game dynamics

We consider the coupled dynamics of the adaption of network structure and the evolution of strategies played by individuals occupying the network vertices. We propose a computational model in which each agent plays a $n$-round Prisoner's Dilemma game with its immediate neighbors, after that, based upon self-interest, partial individuals may punish their defective neighbors by dismissing the social tie to the one who defects the most times, meanwhile seek for a new partner at random from the neighbors of the punished agent. It is found that the promotion of cooperation is attributed to the entangled evolution of individual strategy and network structure. Moreover, we show that the emerging social networks exhibit high heterogeneity and disassortative mixing pattern. For a given average connectivity of the population and the number of rounds, there is a critical value for the fraction of individuals adapting their social interactions, above which cooperators wipe out defectors. Besides, the effects of the average degree, the number of rounds, and the intensity of selection are investigated by extensive numerical simulations. Our results to some extent reflect the underlying mechanism promoting cooperation.Comment: 13 pages, 6 figure

How can innovation economics benefit from complex network analysis?

There is a deficit in economics of theories and empirical data on complex networks, though mathematicians, physicists, biologists, computer scientists, and sociologists are actively engaged in their study. This paper offers a focused review of prominent concepts in contemporary thinking in network research that may motivate further theoretical research and stimulate interest of economists. Possible avenues for modelling innovation, considered the driving force behind economic change, have been explored. A transition is needed from the analysis in economics of the transaction to the explicit examination of market structure and how it processes, or is processed by, innovation.Network; statistics; economy; innovation; modelling

ACCESS: An Inception Report

Imagine a world in which all groups of citizens coming together to realize some public benefit measure and communicate the character and consequences of their work. Imagine further that all those groups have adopted a common reporting system that enables their individual reports to be compared, thus creating powerful descriptions of the relative and collective performance of citizen association for public benefit. Imagine, too, that this common measuring and reporting carries across to all forms of public-private partnership and corporate social responsibility. This is the world envisioned by ACCESS.For the past 18 months a growing number of concerned actors have been meeting, studying, and testing opinion around one of the great structural weaknesses in the world's institutional infrastructure -- inefficient and weak social investment markets. This inception report sets out the results of this enquiry in the form of a proposal to establish a reporting standard for nonprofit organizations seeking to produce social, environmental and, increasingly, financial returns. The ACCESS Reporting standard is one important contribution to redressing a major global system weakness, but it is certainly not the only one. Nor is it one that can operate in isolation from other initiatives. Accordingly, the ACCESS proposed plan of work involves convening a global dialogue on NGO transparency, accountability and performance with the objective of promoting ACCESS and other practical solutions to the challenges of social investment and civil society accountability.This report sets out the background and rationale for these proposals. You will meet the ACCESS sponsors and pilot project partners. Parts of the report are descriptive and analytical but other parts are necessarily theoretical and technical in nature. We make no apology for this. Part of the reason that in 2003 the world does not yet have a reporting standard for social actors is that the theory and technique have not been mastered. For those with a strong orientation toward strategy and action, however, these aspects are presented as well