Characterizing correlations and synchronization in collective dynamics

Synchronization, that occurs both for non-chaotic and chaotic systems, is a striking phenomenon with many practical implications in natural phenomena. However, even before synchronization, strong correlations occur in the collective dynamics of complex systems. To characterize their nature is essential for the understanding of phenomena in physical and social sciences. The emergence of strong correlations before synchronization is illustrated in a few piecewise linear models. They are shown to be associated to the behavior of ergodic parameters which may be exactly computed in some models. The models are also used as a testing ground to find general methods to characterize and parametrize the correlated nature of collective dynamics.Comment: 37 pages, 37 figures, Late

Cooperation, Punishment, Emergence of Government, and the Tragedy of Authorities

Under the conditions prevalent in the late Pleistocene epoch (small hunter-gatherer groups and frequent inter-group conflicts), coevolution of gene-related behavior and culturally transmitted group-level institutions provides a plausible explanation for the parochial altruistic and reciprocator traits of most modern humans. When, with the agricultural revolution, societies became larger and more complex, the collective nature of the monitoring and punishment of norm violators was no longer effective. This led to the emergence of new institutions of governance and social hierarchies. The transition from an egalitarian society and the acceptance of the new institutions may have been possible only if, in the majority of the population, the reciprocator trait had become an internalized norm. However, the new ruling class has its own dynamics, which in turn may lead to a new social crisis. Using a simple model inspired by previous work by Bowles and Gintis, these effects are studied here

Are mutual fund investors in jail?

The absence of investor reaction to the poor performance of mutual funds is a widely reported phenomenon. This paper investigates the role of load costs as an explanation for the phenomenon and concludes that back-end load fees are an obstacle to reaction. We find that investors with a high likelihood of undergoing a liquidity crisis, preferring liquidity in decision making, act contrary to the reaction hypothesis, and investors with broader investment horizons do not react to poor performances due to the fact that they are “imprisoned” by back-end load fees.Mutual Fund, Performance Reaction, Load Costs, Investor Behaviour

Mutual fund flows’ performance reaction: does convexity apply to small markets?

In this paper we study the performance reaction of investors in a small market context. Instead of the asymmetrical investors’ reaction to winners and losers, as usually documented for the US, an absence of risk-adjusted performance reaction was observed. The absence of reaction can be attributed to either lower investor sophistication, conflicts of interests in the context of the Portuguese universal banking industry, or the existence of relevant back-end load cost which prevent investors from reacting. A high persistence of net investment flows was also noted. Our results are consistent with the idea that the financial groups with larger market shares have the capacity “to drive” their customers to funds with larger fees. This practice emerges as a non-transparent means of increasing prices.Mutual Funds, Performance Reaction, Investor Behaviour, Small Markets and Regulation

The great good place : coworking como espaço para aprender design uma framework exploratória

Abstract : In this paper we explore a conceptual framework based on three lines of thinking/work from Patrick Cohendet (Underground/Middleground/Upperground), Ray Oldenburg (The Great Good Place), and Fred Garneti (Heutagogy or Self-determined Learning). To demonstrate the relevance and feasibility of our proposed concept, we review the key factors and definitions of these authors and their work. Although not a theoretical framework, the present paper aims to help us map a part of our research work within the context of the Doctoral Programme in Design at IADE / Universidade Europeia, which triangulates Coworking, Design Learning, and Heutagogy or selfdetermined modes of learning. Ultimately, the aim is to generate new evidence on how such a model of Coworking Design Learning can benefit and betier suit contemporary Design learners.Neste artigo, exploramos uma estrutura conceptual baseada em três linhas de pensamento dos autores Patrick Cohendet (Underground / Middleground / Upperground), Ray Oldenburg (The Great Good Place) e Fred Garneti (Heutagogy or Self-determined Learning). Para demonstrar a relevância e a viabilidade da nossa proposta conceptual, revisitamos os principais fatores e definições destes autores e dos seus trabalhos. Embora não constitua uma framework teórica, o presente trabalho tem como objetivo ajudar a mapear parte do nosso trabalho de pesquisa no contexto do Programa de Doutoramento em Design do IADE / Universidade Europeia, que triangula Coworking, Aprendizagem de Design e Heutagogia ou modos autodeterminados de aprendizagem. Em última instância, o objetivo é tentar produzir novas evidências sobre como um modelo de aprendizagem de Design baseado em espaços de Coworking pode beneficiar e adequar-se melhor aos actuais alunos de Design.info:eu-repo/semantics/publishedVersio

Evolution of networks

We review the recent fast progress in statistical physics of evolving networks. Interest has focused mainly on the structural properties of random complex networks in communications, biology, social sciences and economics. A number of giant artificial networks of such a kind came into existence recently. This opens a wide field for the study of their topology, evolution, and complex processes occurring in them. Such networks possess a rich set of scaling properties. A number of them are scale-free and show striking resilience against random breakdowns. In spite of large sizes of these networks, the distances between most their vertices are short -- a feature known as the ``small-world'' effect. We discuss how growing networks self-organize into scale-free structures and the role of the mechanism of preferential linking. We consider the topological and structural properties of evolving networks, and percolation in these networks. We present a number of models demonstrating the main features of evolving networks and discuss current approaches for their simulation and analytical study. Applications of the general results to particular networks in Nature are discussed. We demonstrate the generic connections of the network growth processes with the general problems of non-equilibrium physics, econophysics, evolutionary biology, etc.Comment: 67 pages, updated, revised, and extended version of review, submitted to Adv. Phy

Contagion effects of the US Subprime Crisis on Developed Countries

This study assesses whether capital markets of developed countries reflect the effects of financial contagion from the US subprime crisis and, in such case, if the intensity of contagion differs across countries. Adopting a definition of contagion that relates the phenomenon to an increase of cross-market linkages following a shock, copula models are used to analyse how the connections between the US and each market in the sample, evolved from the pre-crisis to the crisis period. The results suggest that markets in Canada, Japan, Italy, France and the United Kingdom display significant levels of contagion, which are less relevant in Germany. Canada appears to be the country where the highest intensity of contagion is observed.G7, subprime crisis, contagion, copula, event study.

Suitable methods for landscape evaluation and valorization: the third dimension in landscape metrics

Landscape metrics have been widely developed over the last two decades. One of the major recent developments in landscape metrics analysis was the integration of the third dimension. Topography has an extremely important role in ecosystems function and structure, even though the common analysis in landscape ecology only considers a planimetric surface, which leads to some erroneous results particularly in mountain areas. In this study we tested landscape metrics behaviour in 13 sample areas of 10,000 m2 each in several topographical conditions of Central Alentejo, Portugal. The significance analysis of the results achieved in planimetric and three-dimensional environments is presented