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Product differentiation trade models have been developed in order to account for some contemporary patterns of international trade that are inexplicable under the theory of comparative advantage. This paper presents the case for the geographical differentiation of products. A generalized geographical product differentiation model of trade competition in industrial third markets is outlined within a discrete choice framework. The model treats product price and quality, as determined by country of origin, as distinct variables in export competition. An indirect empirical test of the model's validity, using the cases of export competition between the United States and the Federal Republic of Germany and the United States and Japan, indicates that the generalized model is worthwhile in its ability to account for successful trade competition.  相似文献   
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Maya Blue, a nano-structured clay–organic complex of palygorskite and indigo, was used predominantly before the Spanish Conquest. It has fascinated chemists, material scientists, archaeologists and art historians for decades because it is resistant to the effect of acids, alkalis, and other reagents, and its rich color has persisted for centuries in the harsh tropical climate of southern Mesoamerica. One of its components, palygorskite, is part of modern Maya indigenous knowledge, and ethnohistoric and archaeological data suggest that its modern sources were probably utilized in Prehispanic times. Yet no direct evidence verifies that palygorskite was actually mined from these sources to make Maya Blue. Here we characterize these sources compositionally, and compare our analyses to those of Maya Blue from Chichén Itzá and Palenque. We demonstrate that the palygorskite in most of these samples came from modern mines, providing the first direct evidence for the use of these sources for making Maya Blue. These findings reveal that modern Maya indigenous knowledge about palygorskite, its mining, and its source locations, is at least seven centuries old.  相似文献   
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The Arab–Israeli War of 1948 produced complex questions that needed to be solved to obtain peace. Whereas the Arab states suffered humiliating defeats, Israel was the undisputed winner, expanding and solidifying its power. For the Palestinians, the outcome was catastrophic. Between 600,000 and 760,000 Palestinians fled, becoming refugees on the West Bank, the Gaza Strip, and in surrounding Arab states. Palestinian society collapsed and Palestine became divided between Israel, Egypt, and Jordan, leaving the borders undecided. The Palestinians’ dreams of statehood were crushed. After the war, Israel used diplomacy to achieve its goals, defending the post-war status quo to preserve its expanded territory and resisting the return of Palestinian refugees. Through its membership in the Palestine Conciliation Commission (PCC), established by the United Nations (UN) in 1948 to solve these problems, the United States was deeply involved in the negotiations. The United States became the informal, yet undisputed leader of the PCC, thus, it would seem, empowering it with the muscles of a superpower. After three years of struggling for peace the PCC had toadmit failure. Knowledge about these negotiations gives important insights into how mediators approached the conflict and shows that power asymmetry may explain why the belligerents could not obtain peace.  相似文献   
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