Food for all: An agent-based model to explore the emergence and implications of cooperation for food storage

Abstract

A consistent access to food is paramount for humans at individual and group level. Besides providing the basic nutritional needs, access to food defines social structures and has stimulated innovation in food procurement, processing and storage. We focus on the social aspects of food storage, namely the role of cooperation for the emergence and maintenance of common stocks. Cooperative food stocks are examined here as a type of common-pool resource, where appropriators must cooperate to avoid shortage (i.e. the tragedy of commons). ‘Food for all’ is an agent-based model in which agents face the social dilemma of whether or not to store in a cooperative stock, adapting their strategies through a simple reinforcement learning mechanism. The model provides insights on the evolution of cooperation in terms of storage efficiency and considering the presence of social norms that regulate reciprocity. For cooperative food storage to emerge and be maintained, a significant dependency on the stored food and some degree of external pressure are needed. In fact, cooperative food storage emerges as the best performing strategy when facing environmental stress. Likewise, an intermediate control over reciprocity favours cooperation for food storage, suggesting that concepts of closed reciprocity are precursors to cooperative stocks, while excess control over reciprocity is detrimental for such institution.     

Isotopic Evidence for Marine Consumption and Mobility in the Atacama Desert (Quillagua,Northern Chile)

Archaeological research in the Atacama Desert has recovered evidence of considerable cultural variability. This variability seems to have increased during the Late Intermediate Period (AD 950–1400). The oasis of Quillagua, located at the margins of the Loa River in northern Chile, between the Andes and the coast (70 km from the Pacific Ocean), has shown important evidence regarding this cultural diversity. The variety in the archaeological evidence found at Quillagua has been interpreted as the result of two different cultural influences at the oasis: the Pica‐Tarapacá who occupied the coastal and inland regions to the north of Quillagua and the Atacama who occupied the oasis and fertile areas southeast of Quillagua. Here, we present the results of stable carbon, nitrogen and oxygen isotope analyses of 23 individuals recovered from the Cementerio Oriente in Quillagua, in order to test whether the observed cultural variability is also reflected in diet and mobility patterns. Results from carbon and nitrogen isotope measurements indicate the importance of marine protein, as well as a contribution of maize in the diet of some individuals. Four individuals show low δ¹⁸O values, suggesting a possible highland or non‐local origin, whereas values for the remaining individuals are consistent with lowland populations. Together, the results support the idea that the Quillagua oasis represented an important site of interaction between the Tarapacá and Atacama cultures, with close contacts with the coast but also with the presence of individuals from the highlands. Copyright © 2015 John Wiley & Sons, Ltd.     

Collaborative Networks for Effective Ecosystem‐Based Management: A Set of Working Hypotheses

Ecosystem‐based management (EBM) represents a comprehensive approach to better govern the environment that also illustrates the collaborative trend in policy and public administration. The need for stakeholder involvement and collaboration is strongly articulated, yet how and for what purposes collaboration would be effective remains largely untested. We address this gap by developing and evaluating a set of hypotheses specifying how certain patterns of collaborations among actors affect their joint ability to accomplish EBM. Content analyses of management plans drawn from five EBM planning processes in Sweden are combined with analyses of the collaborative networks through which these plans have been developed. Our results indicate that system thinking and the ability to integrate across different management phases are favored by collaborations between different kinds of actors, and by project leaders being centrally located in the networks. We also find that dense substructures of collaboration increase the level of specificity in the plans in regards to explicating constraints on human activities. Having many collaborative ties does however not enhance the overall level of specificity. Our results also show that different network characteristics can give rise to similar EBM outcomes. This observed equifinality suggests there is no single blueprint for well‐performing collaborative networks.     

Can Russia Break the "Resource Curse"?

A noted European economist argues that the Russian economy and its post-2000 growth have been heavily dependent on natural resources, especially hydrocarbons, and are bound to remain so for some time to come. Given that many economists have come to view rich natural resource endowments as a "curse" that undermines development, the question arises as to whether Russian economic development is doomed. The author argues that while the challenges posed by resource dependence are serious, they can be overcome, or at least substantially mitigated, if accompanied by the right economic policies as the examples of Australia, Canada, and the Scandinavian countries demonstrate. He analyzes what these economic policies are for Russia, and how to set up Russian economic and political conditions to facilitate their implementation. Journal of Economic Literature, Classification Numbers: E6, O1, O52, P2, Q43. 4 figures, 2 tables, 50 references.     

China's "Dash for Gas": Challenges and Potential Impacts on Global Markets

Two UK-based researchers examine the significant recent growth in China's demand for natural gas, a fuel not long ago considered of marginal importance but now viewed as critical for the country's future economic growth. Based on a range of databases as well as industry and media reports, the authors demonstrate how rapid demand growth since 2005 has transformed China from a minor, self-sufficient gas producer to a major buyer on international gas markets. They also analyze projections for future demand growth (25 years), showing China's demand for gas will grow faster that anywhere else in the world, and explore the potential for development of China's substantial domestic gas reserves to mitigate import demand over the short to medium term. The study concludes with an assessment of China's potential impact on global gas markets over short, intermediate, and long time horizons.     

China's Energy Future: A Framing Comment

A noted Hong Kong-based specialist on China's energy industries presents a comment on three papers comprising a symposium on that country's rapidly expanding oil, natural gas, and nuclear power sectors. He frames his observations around five overarching themes that have shaped China's energy sector development over recent decades and will continue to do so in the future. These include observations to the effect that: (a) China's energy policy seeks broadly similar objectives to those of other countries; (b) the country's energy resource endowment is not particularly rich when viewed in relation to the size of its population; (c) its energy mix continues to be dominated by coal, with important implications for the environment and domestic freight transportation; (d) the country's economy is confronting a pronounced spatial mismatch between the location of energy resources and the markets where they are consumed; and (e) strategies for energy developments in China are closely tied to overriding political and economic concerns at any given point in time.     

The lenses of nationhood: an optical model of identity

ABSTRACT. This paper tries to make the case for a model of political identity based on an optical metaphor, which is especially applicable to nations. Human vision can be separated into sentient object, lenses and inbuilt mental ideas. This corresponds well to identity processes in which ‘light’ from a bounded territorial referent is refracted through various lenses (ideological, material, psychological) to focus in certain ways on particular symbolic resources like genealogy, history, culture or political institutions. Distinguishing between referent, lenses and resources helps us more precisely situate many hitherto disparate problems of national identity. These include the ‘ethnic‐civic’ dilemma, the mystery of national identity before nationalism, and the relationship between local and national, and individual and collective, identities. The model also clarifies the place of universalist ideology, which currently fits poorly within the leading culturalist and materialist theories of nationalism.     

Modelling of hydrology and potential population levels at Bronze Age Jawa,Northern Jordan: a Monte Carlo approach to cope with uncertainty

An annual water balance model for Wadi Rajil, in Northern Jordan, is used to simulate the ancient water supply system for the Early Bronze Age site of Jawa. The model includes: water delivery from the catchment; local pond storage; and water demand for people, animals and irrigation. A Monte Carlo approach is used to incorporate the uncertainty associated with a range of factors including rainfall, evaporation, water losses and use. The stochastic simulation provides estimates of potential population levels sustainable by the water supply system. Historical precipitation estimates from a Global Circulation Model, with uncertainty bounds, are used to reconstruct the climate at Jawa in the Early Bronze Age (EBA). Model results indicate that the population levels in the predicted wetter conditions during parts of the EBA could have risen to ∼6000 and may have been higher in wet years. However, palaeoclimatic proxies also suggest prolonged droughts in the EBA; and during these periods the water management system was unable to provide adequate supply for a population of 6000. The utility of Monte Carlo based hydrological modelling as a tool within archaeological science is discussed.     

The consilience of historical and isotopic approaches in reconstructing the medieval Mediterranean diet

During the Middle Ages, the economies of Europe, the religious directives involving dietary requirements, and the general human subsistence base were transformed. These complicated and intertwined issues are starkly revealed in an isotopic study of two inland Italian human populations that are separated by approximately 850 years in time. Stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopic values observed in human dentin and bone collagen from the sites of early medieval Castro dei Volsci and late medieval Rome are consistent with diets that differed substantially. As the North Atlantic opened to fishing and food preservations methods improved, Mediterranean peoples increased their fish consumption dramatically, and in doing so, met the religious directives of the Catholic Church. By analyzing both teeth and bone collagen within individuals, long-term feeding behaviors are documented, and the utility of last erupted teeth collagen as sources of adult dietary information is established. This study offers the first physical evidence of this new economic reality linking the Atlantic and Mediterranean economies at the end of the Middle Ages.     

网络时代与现代酒店整体运作的E模式

本以“信息”作为创新资源予以整合,诠释了现代酒店的信息管理(E)模式在网络时代的全新运作及其对传统酒店经营管理带来的新理念、新思考。