How did a network of marine protected areas impact adjacent fisheries? Evidence from Australia

Marine‐protected areas (MPAs) are an effective means of improving habitat quality and biodiversity in the world’s oceans. While the advantages of MPAs as a mechanism for conservation and biodiversity are well established, the potential improvements to fishery performance resulting from a network of MPAs are still being established. Countries around the world have committed to establishing networks of MPAs within their waters by 2020, in response to the United Nations Convention on Biological Diversity. This, coupled with the increasing global demand for seafood and heavy reliance on fishery resources as a source of economic development for many coastal communities, means that an understanding of how these networks can be expected to impact fishery performance is extremely important. We use a difference‐in‐difference modelling approach to isolate the change in the fishery performance associated with the south‐east marine reserve network in Australia. We find no evidence that the economic performance of adjacent fisheries was negatively impacted by the network. This lack of impact is likely due to a network design explicitly intended to avoid effort displacement in key fisheries, along with fishery management changes intended to remove excess fishing capacity.     

Interventions in Markets with Adverse Selection: Implications for Discount Window Stigma

I study the implications for central bank discount window stigma of a workhorse model of adverse selection in financial markets. In the model, firms (banks) need to borrow to finance a productive project. There is limited liability and firms have private information about their ability to repay their debts, which gives rise to the possibility of adverse selection. The central bank can ameliorate the impact of adverse selection by lending to firms. Discount window borrowing is observable and it may be taken as a signal of firms' credit worthiness. Under some conditions, firms borrowing from the discount window may pay higher interest rates to borrow in the market, a phenomenon often associated with the presence of stigma. I discuss these and other outcomes in detail and what they suggest about the relevance of stigma as an empirical phenomenon.     

中国外汇储备适度规模实证分析

截至2007年底,中国外汇储备突破1.5万亿美元,建立计量模型对中国外汇储备规模进行实证分析表明：自2001年以来中国外汇储备实际规模一直大于适度规模。应扩大内需,酌情开征外汇交易税,适度进行汇率改革,以缓解外汇储备过快增长的局面。     

深层页岩气吸附模型和物质平衡新方法

准确评价深层页岩气井单井最终可采储量（EUR）对页岩气的高效开发具有重要意义。调研深层页岩气吸附模型,基于各模型对吸附数据的拟合程度优选出了考虑深层页岩气吸附因素的T-Langmuir模型。基于T-Langmuir模型表征的深层页岩气吸附特征和流动物质平衡方程基本原理,建立考虑深层页岩气吸附特征的流动物质平衡新方法,并计算了四川盆地某页岩气井的单井最终可采储量。研究结果表明：T-Langmuir模型在高压条件下拟合效果较好,可以作为深层页岩气的吸附模型。新方法计算的单井最终可采储量为1.397×108 m3,比传统方法的计算结果大0.109×108 m3,经过和其他方法对比,新方法计算结果更为准确。     

西北干旱区玛纳斯河流域土地宜耕性评价

[目的]立足西北干旱区土地开垦与弃耕频繁的土地利用现象,揭示西北干旱区耕地后备资源与不稳定耕地之间的相互联系,以玛纳斯河流域为案例区进行研究,为西北干旱区内陆河流域土地利用与生态保护提供建议。[方法]文章运用层次分析法构建评价指标体系,采用综合因子得分法与限制性因子结合法进行土地宜耕性评价,并分别给出空间利用对策。[结果]玛纳斯河流域生态敏感性呈“中间大两头小”的数量结构,敏感区面积较大,极敏感及一般敏感区面积都较小;玛纳斯河流域耕地后备资源综合本底条件多为“较好”及“一般”,但开发受生态敏感性影响较大;玛纳斯河流域混合型不稳定耕地及生态型不稳定耕地面积较大,分别为85 684.77hm2、82 011.87hm2,可优先退耕。[结论]玛纳斯河流域土地资源丰富,但开发利用受生态约束较大,其宜耕耕地后备资源的合理开发,不稳定耕地的生态退耕,对生态安全及粮食安全具有重要作用。     

中国大豆外贸依存度影响因素分析

本文利用年度数据,测算了1988—2007年中国大豆外贸依存度,并对中国大豆外贸依存度的变化趋势特征进行了分析。在此基础上,构建了中国大豆外贸依存度实证模型,定量分析了中国大豆外贸依存度的影响因素。研究结果表明:国内大豆压榨需求和大豆关税税率的变化对中国大豆外贸依存度具有显著影响;而国内外大豆价格差、外汇储备以及实施转基因安全管理条例等因素对中国大豆外贸依存度的影响不显著。     

祁连山国家级自然保护区有效管理评价研究

全面调查分析了祁连山国家级自然保护区管理现状,依据《自然保护区有效管理评价技术规范》原则、方法,对甘肃祁连山国家级自然保护区有效管理进行了评价,综合评价有效管理质量等级为良,说明祁连山国家级自然保护区管理工作有较好的基础。但是,经费管理、保护管理设施、社区协调性3项指标的评价分较低,工作差距较大。规划设计和生态旅游管理工作还存在很大问题。权属、总体规划、边界、范围、设施设备种类和数量、保护区控制、资源监测、社区参与、生态旅游管理9项指标管理质量等级为中等,管理工作还有很大不足,对保护区建设发展造成了不利影响。     

近代上海标金市场金银比价的实证分析及对当代的启示

近代上海标金市场是国际金融市场的重要组成部分,也是上海成为国际金融中心的标志。本文通过实证分析得出,近代上海不仅拥有门类齐全的货币市场和资本市场,重要的是拥有当时世界上最发达、最先进的金融期货市场,这对于当代上海重建国际金融中心具有一定的启发意义。     

Ruin Probabilities for Insurance Models Involving Investments

In this paper we study the ruin problem for insurance models that involve investments. Our risk reserve process is an extension of the classical Cramér-Lundberg model, which will contain stochastic interest rates, reserve-dependent expense loading, diffusion perturbed models, and many others as special cases. By introducing a new type of exponential martingale parametrized by a general rate function, we put various Cramér-Lundberg type estimations into a unified framework. We show by examples that many existing Lundberg-type bounds for ruin probabilities can be recovered by appropriately choosing the rate functions.     

自然保护区旅游开发与环境保护

如何处理好旅游开发与资源,环境保护之间的关系,已经成为学者们关注的重要课题。讨论了自然保护区进行旅游开发的重要性。针对不同类型的自然保护区。提出了不同的旅游开发策略。对旅游开发中存在的资源和环境问题提出了保护措施。