Financial integration and the price of world covariance risk: Large- vs. small-cap stocks

We investigate whether recent country-level evidence of global pricing is particular to large-cap stocks. Specifically, we examine cross-country return correlations and conduct asset pricing tests on three size-based stock portfolios for nine developed countries over the period from 1980 to 2004. We find that large-cap stocks realize significant comovements across countries, whereas small-cap stocks realize smaller average correlations (relative to both large-cap stocks and small-cap stocks across countries). More important, asset pricing tests suggest that while large-cap stocks are priced globally, global pricing is rejected for most small-cap stocks. Finally, the evidence indicates that financial integration deepened in recent years primarily for large-cap stocks. Overall, the results suggest that the global pricing pertains chiefly to large-cap stocks.     

Developing habitat associations for fishes in Lake Winnipeg by linking large scale bathymetric and substrate data with fish telemetry detections

Understanding relationships between freshwater fishes and habitat is critical for effective fisheries and habitat management. Habitat suitability indices (HSI) are commonly used to describe fish–habitat associations in rivers and other freshwater ecosystems. When applied to large lakes however, standard sampling procedures are inadequate because of larger sampling areas and an increased risk of fish collection bias through one-time observations. Here, we use lake bathymetry, substrate, and multiple fish telemetry detections collected from a systematically deployed receiver grid to develop HSI for four fish species (lake sturgeon, freshwater drum, common carp, and walleye) in Lake Winnipeg. Seasonal variations in habitat use based on water depth and substrate were observed in three of four species. Lake sturgeon remained in shallow locations with predominantly gravel substrate near the mouth of the Winnipeg River regardless of season. Freshwater drum persisted over fine substrate in both summer and winter but had a broader depth range in the summer compared to winter. Common carp shifted from mid-range depths and silt substrate in the summer to shallow depths and gravel substrate in the winter. Walleye showed an unchanging association to fine substrate but expanded from primarily mid-range depths in the summer to include shallower depths in the winter. These findings show how multiple telemetry detections per fish can be combined with hydroacoustic data to provide informative habitat associations for fishes in a large lacustrine ecosystem.     

Towards improving an Area of Concern: Main-channel habitat rehabilitation priorities for the Maumee River

The Maumee River watershed in the Laurentian Great Lakes Basin has been impacted by decades of pollution and habitat modification due to human settlement and development. As such, the lower 35 km of the Maumee River and several smaller adjacent watersheds comprising over 2000 km² were designated the Maumee Area of Concern (AOC) under the revised Great Lakes Water Quality Agreement in 1987. As part of pre-rehabilitation assessments in the Maumee AOC, we assessed fish and invertebrate communities in river km 24–11 of the Maumee River to identify: 1) areas that exhibit the highest biodiversity, 2) habitat characteristics associated with high biodiversity areas, 3) areas in need of protection from further degradation, and 4) areas that could feasibly be rehabilitated to increase biodiversity. Based on benthic trawl data, shallow water habitats surrounding large island complexes had the highest fish diversity and catch per unit effort (CPUE). Electrofishing displayed similar fish diversity and CPUE patterns across habitat types early in the study but yielded no discernable fish diversity or CPUE patterns towards the end of our study. Although highly variable among study sites, macroinvertebrate density was greatest in shallow water habitats <2.5 m and around large island complexes. Our results provide valuable baseline data that could act as a foundation for developing rehabilitation strategies in the lower Maumee River and for assessing the effectiveness of future aquatic habitat rehabilitation projects. In addition to increasing in-channel habitat, watershed-scale improvements of water quality might be necessary to ensure rehabilitation strategies are successful.     

基于山区地质灾害危险性分区的建设用地适宜性评价

地质灾害是建设用地选址时考虑的关键因素之一,也是危险性区划的主要参考要素,其直接或间接危害到人类安全并给社会和经济建设造成重大损失。为了降低建设用地规划中地质灾害的影响,应将地质灾害危险性分区考虑到建设用地适宜性评价当中。以干旱河谷山区丹巴县为研究区,运用确定系数和逻辑回归相结合的方法,构建地质灾害危险性评价体系对该区进行地质灾害危险性分区。选择安全因子、自然因子、社会因子和生态因子共同构成建设用地适宜性评价指标体系,利用层次分析法对研究区进行建设用地适宜性评价。结果表明:(1)对丹巴县进行危险性分区,极高危险区217.20km2,高危险区744.95km2,中度危险区1352.44km2,低度危险区1295.08km2以及极低危险区875.32km2。(2)丹巴县建设用地最适宜区面积为115.72km2,占县域总面积的2.57%,适宜建设的土地少且多集中在小金川、革什扎河、东谷河和大渡河沿岸河谷地区。较适宜区、基本适宜区、较不适宜区和禁止建设区面积分别为683.47km2、623.21km2、590.66km2、2494.21km2。(3)已建成的城镇空间中38.50%和37.62%分布在最适宜区和较适宜区,整体分布状况良好。有5.85%的城镇空间建设在较不适宜区,2.67%在禁止建设区,存在生态安全风险,该区域应加强灾害预警与防灾减灾工作,有条件地适度搬迁。     

Analysis of cointegrated VARMA processes

VARMA (vector autoregressive moving average) processes are proposed for modelling cointegrated variables. For this purpose the echelon form is combined with the error correction form. Procedures for estimating the Kronecker indices which characterize the echelon form and for specifying the cointegration rank are discussed. The asymptotic distribution of the coefficient estimators is given. An example based o n US macroeconomic data illustrates the procedure and demonstrates its feasibility in practice.     

The productivity of private and social farms: Multilateral Malmquist indices for Slovene dairying enterprises

Applying programming techniques to farm-level panel data for four cooperative and 12 private dairy farms in the Yugoslav Republic of Slovenia gives estimates of technical efficiency, scale efficiency, and technical progress. These are used to construct multilateral Malmquist indices of total factor productivity (TFP). For the cooperatives, TFP growth has been slow and is attributable to technical progress. For the private farms, technical progress was also slow, but TFP growth was faster due to improved efficiency. Scale inefficiency explains the poorer absolute performance of the private farms, indicating the need for land reform as well as technological change.     

我国切花出口国际竞争力的实证分析

花卉产业是世界农业中惟一不受农产品配额限制的产业。切花产品已经成为国际上的大宗商品，对于切花的需求逐年增长。我国地大物博，气候条件多样，适于种植花卉。作为世贸组织成员国，近年来切花出口增长的趋势明显。本文运用贸易竞争指数、市场占有率、市场集中度和显示性比较优势指数，从我国切花产品与国际市场相对应的角度，定量比较分析我国切花产品国际竞争力，并分析影响切花国际竞争力的主要因素，从而对优化我国切花产品的出口环境提出相应建议。     

基于适宜性的西安市水源热泵开发潜力评估

依据适宜性评价,综合考虑水质、回灌率、已运行情况以及环境条件对水源热泵开发的影响,对西安市水源热泵开发利用潜力进行评估。结果表明:西安市适宜性面积占研究区总面积31.52%;将西安市水源热泵开发潜力划分为5类潜力类型区:Ⅰ、Ⅱ类潜力区主要分布于西安市北部,以平原为主,为开发潜力优、良区;Ⅲ类潜力区主要分布于临潼中部、阎良东部、长安南部、户县和周至南部等地,为适度开发潜力区;Ⅳ类潜力区主要分布于蓝田西南、临潼南部以及长安丘陵区,为不宜开发潜力区;Ⅴ类地区为秦岭山地和禁采区,应限制水源热泵的开发利用。研究可确定西安市不同地域的水源热泵开发利用潜力,研究结果可为编制西安市水源热泵开发规划提供参考。     

A note on the ecological-economic modelling of marine reserves in fisheries

This paper gives an overview of the bioeconomic modelling of marine reserves, and illustrates how economists have responded to the modelling results found in the ecological literature. The economic analysis is shown to be far more pessimistic with regards to the potential of marine reserves as a fisheries management tool, than what one finds in the purely ecological analysis, the reason being the latter's neglect of issues such as discounting and economic incentive behaviour. However, economic analysis, despite some of it being relatively advanced with regards to spatiality, is still simplistic with regards to for instance ecosystem and habitat content. A simple expansion of the existing bioeconomic models with regards to positive habitat effects of area closures is presented and analysed, showing room for improved results from marine reserve implementation as compared to the existing analysis.     

基于投影模型的不确定语言型多属性决策方法及应用

研究了不确定语言型多属性决策评价结果与决策者对方案的偏好信息之间存在偏差的问题,提出了基于投影模型的不确定多属性决策方法。该方法通过建立与区间型语言标度对应的术语指标矩阵,及方案综合属性值与决策者主观偏好值之间的投影模型,确定属性的权重,然后运用加权法得到方案的综合属性值,利用已有的可能度矩阵排序公式得到决策方案的排序。最后,通过算例对该方法的实用性和有效性进行了说明。