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ABSTRACT. We determine the location equilibria in a duopoly model under a novel solution concept. Typically, spatial equilibrium is described as either a simultaneous price and location game, or else as a two-stage location-then-price game. We introduce a new alternative, a two-stage price-then-location game. It is well known that no (pure strategy) equilibrium usually exists under the two standard solution concepts when products are homogeneous. We show this is also true for the new concept. We then provide numerical results for a specific functional form (the logit model) which introduces product heterogeneity into the standard framework, restoring equilibrium when the degree of substitutability between products is not too small. 相似文献
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Pierre de Maret 《African Archaeological Review》1986,4(1):103-133
Summary Now, for the first time, it is possible to place in an exact archaeological context the polished tools which have been collected for many years on the surface in the savanna immediately to the south of the equatorial forest. In Lower Zaïre, in an area of 6000 km2, polished tools have been found systematically associated with a particular type of pottery. This pottery, which was previously known as Groupvi pottery and which we propose calling Ngovo group pottery is very distinctive.Although faunal remains associated in one case were of wild animals, someElaeïs andCanarium nuts could indicate the beginnings of agriculture. A series of dates in good agreement place these polished tools and this pottery within the last two centuries bc.At the present time, iron-working in Lower Zaïre has not been dated prior to the second century ad. This Early Iron Age is associated with the Kay Ladio group pottery which is possibly derived from the Ngovo group.
Résumé Pour la première fois, il est possible de préciser le contexte archéologique des outils polis que depuis longtemps on recueillait en surface dans les savanes immédiatement au sud de la forêt équatoriale.Au Bas-Zaïre, dans une zone de plus de 6000 km2, des outils polis ont été trouvés systématiquement en association avec une céramique d'un type particulier. Cette céramique, connue précédemment sous le nom de céramique du groupevi et que l'on propose d'appeler dorénavant groupe de Ngovo, est très caractéristique.Bien que les restes de faune qui y sont associés dans une grotte soient ceux d'animaux sauvages, des noix d'Elaeïs et deCanarium indiquent peut-être un début d'agriculture.Une série de datations remarquablement convergentes placent ces outils polis et cette céramique durant les deux derniers siècles bc.La métallurgie n'est jusqu'à présent pas datée au Bas-Zaïre avant le 2e siècle ad. Cet âge du fer ancien est associé à la céramique du groupe Kay Ladio qui dérive peut-être du groupe de Ngovo.相似文献
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Gas liquid chromatography was used to analyse residues adhering to the inside of excavated potsherds from dated South African sites. The results suggested marine animal fat, possibly seal, had been cooked in the vessels. Fat of modern seals was baked and also analysed as a control sample. This gave similar results. The importance of seals in the prehistoric diet of the Southwestern Cape is supported by a large number of seal bones in the associated faunal material. 相似文献
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The purpose of this paper, prepared as a background document for the UNRISD/University of the West Indies conference on Economic Crisis and Third World Countries, is to provide a framework for consideration of societal changes accompanying economic recession and restructuring in Africa, Latin America and the Caribbean over the past decade. It is the central argument of the paper that adaptation to crisis should not be considered a temporary phenomenon, interrupting a single, lineal process of modernization which can be expected to resume its course once current difficulties are overcome. On the contrary, both crisis and adjustment have profoundly modified the structure of incentives within which individuals and households must attempt to ensure their livelihood, encouraging new patterns of behaviour with long-term implications for the nature of the economy, society and political practice. After a brief review of the macroeconomic background of crisis in each region, this central hypothesis is explored through a very preliminary analysis of the changing life chances of various kinds of upper, middle and lower income groups — emphasizing not only the costs but also the opportunities which have been associated with economic restructuring. Some individual and collective reactions to change are then considered, before raising a series of questions concerning the implications of crisis and adjustment for the state and civil society. 相似文献
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Terri‐Leigh Aldred Charis Alderfer‐Mumma Sarah de Leeuw May Farrales Margo Greenwood Dawn Hoogeveen Ryan OToole Margot W. Parkes Vanessa Sloan Morgan 《The Canadian geographer》2021,65(1):82-96
Rural, remote, northern, and Indigenous communities on Turtle Island are routinely—as Cree Elder Willie Ermine says—pathologized. Social science and health scholarship, including scholarship by geographers, often constructs Indigenous human and physical geographies as unhealthy, diseased, vulnerable, and undergoing extraction. These constructions are not inaccurate: peoples and places beyond urban metropoles on Turtle Island live with higher burdens of poor health; Indigenous peoples face systemic violence and racism in colonial landscapes; rural, remote, northern, and Indigenous geographies are sites of industrial incursions; and many rural and remote geographies remain challenging for diverse Indigenous peoples. What, however, are the consequences of imagining and constructing people and places as “sick”? Constructions of “sick” geographies fulfill and extend settler (often European white) colonial narratives about othered geographies. Rural, remote, northern, and Indigenous geographies are discursively “mined” for narratives of sickness. This mining upholds a sense of health and wellness in southern, urban, Euro‐white‐settler imaginations. Drawing from multi‐year, relationship‐based, cross‐disciplinary qualitative community‐informed experiences, and anchored in feminist, anti‐colonial, and anti‐racist methodologies that guided creative and humanities‐informed stories, this paper concludes with different stories. It unsettles settler‐colonial powers reliant on constructing narratives about sickness in others and consequently reframes conversations about Indigenous well‐being and the environment. 相似文献
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F. Albarde J. Blichert‐Toft F. de Callataÿ G. Davis P. Debernardi L. Gentelli H. Gitler F. Kemmers S. Klein C. Malod‐Dognin J. Milot P. Tlouk M. Vaxevanopoulos K. Westner 《Archaeometry》2021,63(1):142-155
The reasons why the Western Mediterranean, especially Carthage and Rome, resisted monetization relative to the Eastern Mediterranean are still unclear. We address this question by combining lead (Pb) and silver (Ag) isotope abundances in silver coinage from the Aegean, Magna Graecia, Carthage and Roman Republic. The clear relationships observed between 109Ag/107Ag and 208Pb/206Pb reflect the mixing of silver ores or silver objects with Pb metal used for cupellation. The combined analysis of Ag and Pb isotopes reveals important information about the technology of smelting. The Greek world extracted Ag and Pb from associated ores, whereas, on the Iberian Peninsula, Carthaginians and Republican‐era Romans applied Phoenician cupellation techniques and added exotic Pb to Pb‐poor Ag ores. Massive Ag recupellation is observed in Rome during the Second Punic War. After defeating the Carthaginians and the Macedonians in the late second century bce , the Romans brought together the efficient, millennium‐old techniques of silver extraction of the Phoenicians, who considered this metal a simple commodity, with the monetization of the economy introduced by the Greeks. 相似文献