中国种植业产品贸易自由化对环境影响的计量经济分析

入世后．中国将根据WTO的要求对农业贸易相关政策进行调整和改革，这将改变国内农业生产，进而影响到农村生态环境。在此背景下．本文首先界定了种檀业产品贸易自由化的涵义．并对其环境影响途径进行分析．然后利用计量经济方法着重分析了贸易自由化对国内种植业生产中化肥、农药使用的影响。研究结果表明，在种植业产品的贸易自由化中，进口渗透作用对缓解国内化肥、农药污染影响显着．而出口导向作用影响不明显。文章最后给出了减缓农产品贸易自由化的不利影响，发挥其有利影响的政策建议。     

我国土地市场公开交易存在的问题与对策——以徐州市土地市场服务中心为例

以徐州市为例,分析了土地公开交易中在土地需求主体、政府调控、出让方式、交易场所、交易制度和信息更新等方面存在亟需解决的问题,并提出坚持“走出去,引进来”、实行地产策划、加大“净地”出让、推行“网上竞价”、创新制度和土地市场信息系、统等具体,可行的措施。研究认为,我国土地市场建设还不够成熟,建立规范化土地市场是一个长期、复杂的过程,需要长时间实践、探索。     

我国现代人地关系与资源环境基础

在经过了４０ 多年大规模建设,中国工业化发展面临着来自有限资源环境越来越大的压力。从协调人地关系紧张矛盾的角度出发,中国未来经济的发展不仅需要增加资金和科技投入,而且也需要提高资源投入的质量。欲达此目的,扩大资源的国际贸易,特别是石油、天然气的进口就变得十分重要     

The capital gains from trade are not enough: evidence from the environmental accounts of Venezuela and Mexico

In principle, a country cannot endure negative genuine savings for long periods of time without experiencing declining consumption. Nevertheless, theoreticians envisage two alternatives to explain how an exporter of non-renewable natural resources could experience permanent negative genuine savings and still ensure sustainability. The first one alleges that the capital gains arising from the expected improvement in the terms of trade would suffice to compensate for the negative savings of the resource exporter. The second alternative points at technological change as a way to avoid economic collapse. This paper uses the data of Venezuela and Mexico to empirically test the first of these two hypotheses. The results presented here prove that the terms of trade do not suffice to compensate the depletion of oil reserves in these two open economies.     

排污交易——一条污染物总量控制的环境管理手段

本文从环境管理的角度，提出了排污效果这种有效控制污染的管理手段，并从国外的经验、国内背景、具体操作程度等方面论证了我国推行排污交易时机已成熟。     

引入碳价格后中国出口贸易成本的变化

应对气候变化的政策手段多种多样,市场机制手段是目前应用广泛的政策工具之一。国际碳交易的实践尤其是欧盟ETS的运行效果显示,电力及一些能源加工转换行业通常会因为承担了碳交易的成本,而会导致其下游产品价格的发生变动,一般表现在下游电力价格的增加,因此会使得其他行业的生产成本受电力价格的上涨而增加。因此碳价格机制的引入对于整个经济发展的成本产生一定的影响,而我国目前以出口贸易为导向的经济现状,势必使得碳价格影响到出口贸易的产品成本上。本文主要利用我国2005年和2007年的投入产出表,测算我国出口贸易产品能源成本的变化。结果显示我国出口产品的能源成本占每年出口额比重约为13%,若扣除掉消耗进口中间产品的因素,仅仅考虑国内中间投入产品的能源成本,则出口产品中的能源成本比重下降至9%-10%左右,其中电力的成本约占整个能源成本的60%以上,若由于碳价格机制的引入导致电力成本上涨50%,则使得我国出口能源成本的至少上涨一半以上,这将大幅度降低我国出口产品的国际竞争力。因此我国出口贸易的主要部门一方面需要不断加强技术研发投入,提升其生产技术水平,降低能源成本的比重,提高单位产品的能源效率;另一方面由于我国外贸存在较大的顺差,也要不断调整出口产品的结构,配合国内产业政策的调整,降低能源成本较高产品的出口,优化出口产品的结构,提高出口产品的科技含量和附加值,整个贸易政策调整优先向竞争力导向转变。     

Sea Snake Harvest in the Gulf of Thailand

Conservation of sea snakes is virtually nonexistent in Asia, and its role in human–snake interactions in terms of catch, trade, and snakebites as an occupational hazard is mostly unexplored. We collected data on sea snake landings from the Gulf of Thailand, a hotspot for sea snake harvest by squid fishers operating out of the ports of Song Doc and Khanh Hoi, Ca Mau Province, Vietnam. The data were collected during documentation of the steps of the trading process and through interviewers with participants in the trade. Squid vessels return to ports once per lunar synodic cycle and fishers sell snakes to merchants who sort, package, and ship the snakes to various destinations in Vietnam and China for human consumption and as a source of traditional remedies. Annually, 82 t, roughly equal to 225,500 individuals, of live sea snakes are brought to ports. To our knowledge, this rate of harvest constitutes one of the largest venomous snake and marine reptile harvest activities in the world today. Lapemis curtus and Hydrophis cyanocinctus constituted about 85% of the snake biomass, and Acalyptophis peronii, Aipysurus eydouxii, Hydrophis atriceps, H. belcheri, H. lamberti, and H. ornatus made up the remainder. Our results establish a quantitative baseline for characteristics of catch, trade, and uses of sea snakes. Other key observations include the timing of the trade to the lunar cycle, a decline of sea snakes harvested over the study period (approximately 30% decline in mass over 4 years), and the treatment of sea snake bites with rhinoceros horn. Emerging markets in Southeast Asia drive the harvest of venomous sea snakes in the Gulf of Thailand and sea snake bites present a potentially lethal occupational hazard. We call for implementation of monitoring programs to further address the conservation implications of this large‐scale marine reptile exploitation. Cosecha de Serpientes Marinas en el Golfo de Tailandia     

Tracing the geographic origin of traded leopard body parts in the indian subcontinent with DNA‐based assignment tests

Illicit trade in wildlife products is rapidly decimating many species across the globe. Such trade is often underestimated for wide‐ranging species until it is too late for the survival of their remaining populations. Policing this trade could be vastly improved if one could reliably determine geographic origins of illegal wildlife products and identify areas where greater enforcement is needed. Using DNA‐based assignment tests (i.e., samples are assigned to geographic locations), we addressed these factors for leopards (Panthera pardus) on the Indian subcontinent. We created geography‐specific allele frequencies from a genetic reference database of 173 leopards across India to infer geographic origins of DNA samples from 40 seized leopard skins. Sensitivity analyses of samples of known geographic origins and assignments of seized skins demonstrated robust assignments for Indian leopards. We found that confiscated pelts seized in small numbers were not necessarily from local leopards. The geographic footprint of large seizures appeared to be bigger than the cumulative footprint of several smaller seizures, indicating widespread leopard poaching across the subcontinent. Our seized samples had male‐biased sex ratios, especially the large seizures. From multiple seized sample assignments, we identified central India as a poaching hotspot for leopards. The techniques we applied can be used to identify origins of seized illegal wildlife products and trade routes at the subcontinent scale and beyond.     

Trade‐offs among Catch,Bycatch, and Landed Value in the American Samoa Longline Fishery

The interspecific preferences of fishes for different depths and habitats suggest fishers could avoid unwanted catches of some species while still effectively targeting other species. In pelagic longline fisheries, albacore (Thunnus alalunga) are often caught in relatively cooler, deeper water (>100 m) than many species of conservation concern (e.g., sea turtles, billfishes, and some sharks) that are caught in shallower water (<100 m). From 2007 to 2011, we examined the depth distributions of hooks for 1154 longline sets (3,406,946 hooks) and recorded captures by hook position on 2642 sets (7,829,498 hooks) in the American Samoa longline fishery. Twenty‐three percent of hooks had a settled depth <100 m. Individuals captured in the 3 shallowest hook positions accounted for 18.3% of all bycatch. We analyzed hypothetical impacts for 25 of the most abundant species caught in the fishery by eliminating the 3 shallowest hook positions under scenarios with and without redistribution of these hooks to deeper depths. Distributions varied by species: 45.5% (n = 10) of green sea turtle (Chelonia mydas), 59.5% (n = 626) of shortbill spearfish (Tetrapturus angustirostris), 37.3% (n = 435) of silky shark (Carcharhinus falciformis), and 42.6% (n = 150) of oceanic whitetip shark (C. longimanus) were caught on the 3 shallowest hooks. Eleven percent (n = 20,435) of all tuna and 8.5% (n = 10,374) of albacore were caught on the 3 shallowest hooks. Hook elimination reduced landed value by 1.6–9.2%, and redistribution of hooks increased average annual landed value relative to the status quo by 5–11.7%. Based on these scenarios, redistribution of hooks to deeper depths may provide an economically feasible modification to longline gear that could substantially reduce bycatch for a suite of vulnerable species. Our results suggest that this method may be applicable to deep‐set pelagic longline fisheries worldwide. Compensaciones entre Captura, Captura Accesoria y Valores Asentados en la Pesquera de Línea Larga de Samoa Americana     

关于贸易与环境关系的几点认识及其对我国的启示

环境与贸易是环境与发展的热点问题之一。环境与贸易的主要关系问题包括贸易活动本身与环境的关系问题 ,以及贸易规则与环境的关系问题。环境成本外部化是这些问题的根源。我国在新形势下针对这些问题应当采取相应的对策措施。