PRODUCTION TECHNOLOGY UNCERTAINTY AND THE OPTIMAL LOCATION OF THE FIRM*

ABSTRACT This paper investigates the implication of production-technology uncertainty for the exclusion theorem. The paper presents the result that the risk-averse firm facing production technology uncertainty prefers an intermediate location to avoid risk under certain conditions. The firm chooses an intermediate location (over a corner location) particularly if its degree of risk aversion overwhelms the inherent convexity of profit with respect to location. The latter depends, in turn, on the structure of production technology characterized by the elasticity of substitution and returns to scale parameters.     

Mode Choice in a Hub-and-Spoke Network: A Zero-One Linear Programming Approach

While research has tackled the hub-and-spoke network design problem, that research has overlooked the air-truck modal integration issue which is a common feature of real express delivery systems. This paper devises integer linear programs to represent the mode and route assignment aspects of the operational problem. The model is solved under four different levels of delivery schedule, and the results show that as the promised delivery schedule is relaxed, not only does the use of truck routes become more desirable, but also interesting adjustments in mode and hub assignment occur. Consider the case of hubs in Los Angeles and Dayton. As the time constraints are relaxed, cities such as Minneapolis and New Orleans originally linked by air to Los Angeles, switch to Dayton because cheaper truck routes become feasible.     

"承上制下"与"从左转右":北宋物资转输区域的互动——以东南地区为中心

北宋时期,朝廷在淮南地区运河沿岸州军设置转般仓,这些州军具有了转般粮食物资进京的功能;又先后置发运司于真州和泗州,使其开始具有总管东南漕运事务的职能;盐利也集中于此,同时亦掌控着地方物资的上供经费.其他物资转输区域则经常出现改变转运方式的情形,中转区域改变了起始区域输出物资的运输方式,减轻了部分运输成本.起始区域在加重中转区域负担的同时,亦对中转区域的经济繁荣有促进作用.     

Micro-CT-assisted determination of the shattering and non-shattering phenotypes of charred rice spikelet bases from archaeological sites: a new methodological approach

The selection of a non-shattering phenotype is a pivotal change in the process of rice domestication. However, current research is heavily restricted by the preservation conditions of macro-plant remains in early and middle Neolithic sites, as very limited well-preserved rice spikelet bases could be retrieved. We present a non-destructive method based on micro-computed tomographic (CT) scanning, which could provide detailed visualization of the internal structures of charred spikelet bases and efficiently discriminate the shattering and non-shattering phenotypes of rice spikelet bases according to the abundance of fusiform echinate phytoliths. It could be widely applied in different contexts, especially those poorly preserved specimens and tempers in pottery sherds, greatly improving our knowledge of rice domestication.     

Innovation across cities

This paper examines the distribution of patenting activity across cities in the OECD, using a sample of 218 cities from 2000 to 2008. We obtain three main results. First, patenting activity is more concentrated than population and GDP. Second, patenting activity is less persistent than population and GDP, especially in the middle of the distribution. Third, in a parametric model, patenting does not exhibit mean‐reversion, and is positively associated with GDP and population density. Our results suggest that policymakers can influence the amount of innovative activity through the use of appropriate policies.     

AN ARTISTIC LIFE CREATED BY A PAIR OF SKILLFUL HANDS

正The cold season isjust about to arrive in Lhasa.A tallllbetan man is standing upon the golden roof of the Jokhang Temple to look out into distance.His name is Tsegya,a man with a deep affection for this very roof.This is the place where his karma connects him to his produced mandalas.Tsegya told me that     

抗战中的知识分子

作者通过对甲午战争至全面抗战爆发历史的回顾,分析期间中国知识分子的思想变化.并分析抗战爆发后知识分子通过不同的方式积极投入救亡运动,重新认识抗战期间的知识分子的真实处境和历史,提出应更理性、客观的去看待抗战时期的知识分子的选择,无论是自由主义知识分子、马克思主义知识分子还是新儒家知识分子,对近代中国文化的追求,根本上都是“三民主义”.     

明初大运河南旺分水枢纽水工技术考

明朝初年,国脉皆仰东南,为解决南方粮财物的北运问题,宋礼和白英受命组织修建了大运河山东段南旺分水枢纽。该枢纽主要包括引汶济运、导泉补源、设立水柜和置闸节流四个组成部分。其中,引汶济运是工程之重点,包括戴村坝、小汶河、南旺分水以及配套工程等四个子系统。这些水利设施组成一个和谐的系统工程,保证了该段运河的水量稳定充足,从而实现了大运河500余年的正常通行。南旺分水枢纽代表了我国古代运河水工的最高科学技术成就,堪称世界水利史上的一大经典范例。     

Traditions and transitions in Korean bronze technology

Metallurgical examination of Korean bronze artifacts shows that a technical tradition based on casting and use of leaded high-tin alloys was established in Korea at the early stages of bronze use. After the subsequent discovery of quenching methods that suppress formation of the brittle δ phase, new thermo-mechanical techniques were introduced between the 7th and 10th centuries AD. Lead-free alloys were used, and tin contents near that of the peritectic point in the Cu–Sn phase diagram were chosen. Leaded high tin alloys continued in use, but only in cast objects, and with significant composition variation. The unique conditions during the time of innovation suggest that the transition to new metallurgical techniques was gradually achieved through domestic technical innovation inspired by external influences.