The Growth of Oligarchy in a Yard-Sale Model of Asset Exchange: A Logistic Equation for Wealth Condensation

The addition of wealth-attained advantage (WAA) to the Yard-Sale Model (YSM) of asset exchange has been demonstrated to induce wealth condensation. In a model of WAA for which the bias is a continuous function of the wealth difference of the transacting agents, the condensation was shown to arise from a second-order phase transition to a coexistence regime. In this paper, we present the first analytic time-dependent results for this model, by showing that the condensed wealth obeys a logistic equation in time.Comment: 15 pages, 2 figure

Optimal risk in wealth exchange models: agent dynamics from a microscopic perspective

In this work we study the individual strategies carried out by agents undergoing transactions in wealth exchange models. We analyze the role of risk propensity in the behavior of the agents and find a critical risk, such that agents with risk above that value always end up losing everything when the system approaches equilibrium. Moreover, we find that the wealth of the agents is maximum for a range of risk values that depends on particular characteristics of the model, such as the social protection factor. Our findings allow to determine a region of parameters for which the strategies of the economic agents are successful.Comment: 17 pages, 11 figure

Globalization and inequality in an agent-based wealth exchange model

Agent-based asset exchange models serve as an interesting and tractable means by which to study the emergence of an economy's wealth distribution. Although asset exchange models have reproduced certain features of real-world wealth distributions, previous research has largely neglected the effects of economic growth and network connectivity between agents. In this work, we study the effects of globalization on wealth inequality in the Growth, Exchange, and Distribution (GED) model [Liu et al, Klein et al] on a network or lattice that connects potential trading partners. We find that increasing the number of trading partners per agent results in higher levels of wealth inequality as measured by the Gini coefficient and the variance of the agent wealth distribution. However, if globalization is accompanied by a proportionate increase in the economic growth rate, the level of inequality can be held constant. We present a mean-field theory to describe the GED model based on the Fokker-Planck equation and derive the stationary wealth distributions of the network GED model. For large Ginzburg parameter for which mean-field theory is applicable, the wealth distributions for the fully connected model are found to be Gaussian; however, for sparse trade networks, a non-Gaussian "hyperequal" phase is found even for large Ginzburg parameter. It is shown that several networks (Erdos-Renyi, Barabsi-Albert, one-dimensional and two-dimensional lattices) display mean-field critical exponents when the Ginzburg parameter is large and held constant and the system parameters are scaled properly

Self-organization and time-stability of social hierarchies

The formation and stability of social hierarchies is a question of general relevance. Here, we propose a simple generalized theoretical model for establishing social hierarchy via pair-wise interactions between individuals and investigate its stability. In each interaction or fight, the probability of "winning" depends solely on the relative societal status of the participants, and the winner has a gain of status whereas there is an equal loss to the loser. The interactions are characterized by two parameters. The first parameter represents how much can be lost, and the second parameter represents the degree to which even a small difference of status can guarantee a win for the higher-status individual. Depending on the parameters, the resulting status distributions reach either a continuous unimodal form or lead to a totalitarian end state with one high-status individual and all other individuals having status approaching zero. However, we find that in the latter case long-lived intermediary distributions often exist, which can give the illusion of a stable society. As we show, our model allows us to make predictions consistent with animal interaction data and their evolution over a number of years. Moreover, by implementing a simple, but realistic rule that restricts interactions to sufficiently similar-status individuals, the stable or long-lived distributions acquire high-status structure corresponding to a distinct high-status class. Using household income as a proxy for societal status in human societies, we find agreement over their entire range from the low-to-middle-status parts to the characteristic high-status "tail". We discuss how the model provides a conceptual framework for understanding the origin of social hierarchy and the factors which lead to the preservation or deterioration of the societal structure.Comment: Added sections 4.1 and S2.A about agonistic interactions in animals, added sections 4.2.1 and S2.B regarding potential proxies for societal status in non-human animals, added references to sections 1 and 2. Main text: 34 pages, 11 figures. Supplementary appendices: 36 pages, 24 figure

Taiwan and China

China's relation to Taiwan has been in constant contention since the founding of the People's Republic of China in October 1949 and the creation of the defeated Kuomintang (KMT) exile regime on the island two months later. The islands autonomous sovereignty has continually been challenged, initially because of the KMT's insistence that it continue to represent not just Taiwan but all of China and later because Taiwan refused to cede sovereignty to the then-dominant power that had arisen on the other side of the Taiwan Strait. One thing that makes Taiwan so politically difficult and yet so intellectually fascinating is that it is not merely a security problem, but a ganglion of interrelated puzzles. The optimistic hope of the Ma Ying-jeou administration for a new era of peace and cooperation foundered on a landslide victory by the Democratic Progressive Party, which has made clear its intent to distance Taiwan from China's political embrace. The Taiwanese are now waiting with bated breath as the relationship tautens. Why did detente fail, and what chance does Taiwan have without it? Contributors to this volume focus on three aspects of the evolving quandary: nationalistic identity, social economy, and political strategy

Taiwan and China

China's relation to Taiwan has been in constant contention since the founding of the People's Republic of China in October 1949 and the creation of the defeated Kuomintang (KMT) exile regime on the island two months later. The islands autonomous sovereignty has continually been challenged, initially because of the KMT's insistence that it continue to represent not just Taiwan but all of China and later because Taiwan refused to cede sovereignty to the then-dominant power that had arisen on the other side of the Taiwan Strait. One thing that makes Taiwan so politically difficult and yet so intellectually fascinating is that it is not merely a security problem, but a ganglion of interrelated puzzles. The optimistic hope of the Ma Ying-jeou administration for a new era of peace and cooperation foundered on a landslide victory by the Democratic Progressive Party, which has made clear its intent to distance Taiwan from China's political embrace. The Taiwanese are now waiting with bated breath as the relationship tautens. Why did detente fail, and what chance does Taiwan have without it? Contributors to this volume focus on three aspects of the evolving quandary: nationalistic identity, social economy, and political strategy

Handa sa laban araw-araw? (Ready to fight every day?) : Readiness to Political Action and Sense of Entitlement: How strong is Citizenship in the Philippines? With a Special Focus on International Call Center Agents

The aim of this dissertation is to identity the sense of citizenship prevalent in the Philippines. Citizenship here is defined in two respects: an active dimension (exercis-ing voice) and a passive dimension (claiming rights or sense of entitlement). Findings from a series of problem-centered interviews with call center agents are complemented by the outcome of several annual surveys by the International Social Survey Programme (ISSP), especially the ISSP surveys on government (2006), social inequality (2009) and citizenship (2004) and validated by the analysis of media col-umns and societal artefacts over the last 10 years. While the first part of the dissertation analyzes why trade unions and other forms of collective interest representation hardly develop in the call center setting (economic citizenship), the second part identifies readiness to political action and expectations towards the state (political citizenship) in the context of an “informal security re-gime” (Geoff Wood). The main part of the study is followed by a postscript offering an outlook on opportunities and limitations of citizenship in the Philippine social and cultural context. The work contains several theoretical discussions of basic concepts and issues arising when sense of citizenship, especially in a non-European context, is analyzed. These include critiques on the theory of citizenship and on precarity, the middle class(es), citizenship in a non-western context, spaces of the political and post-national citizen-ship. In sum, a sense of citizenship is identified as full of requirements so that the stand-by citizen is rather considered the norm. The work comes to the conclusion that there is no general lack of a sense of citizen-ship among Filipinos. However as they have never experienced a comprehensive public service and consider such “unrealistic,” their expectations as citizens are in practice low. The state is considered as enabler, not as provider, so that self-help is given priority. Such rather communitarian sense of citizenship is identified as con-niving with a neoliberal governementality of responsibilization. Only among those with a left political socialization can a sense of citizenship, as assumed in most schol-arly literature, be identified, with substantial expectations towards the state, demand of accountability and an identity as political subject (professional citizenship)

Towards Sustainable Global Food Systems

environment; food; agriculture; policy; global food system