北京市中心城土地利用变化及其对 生境的影响(1992—2016)

：随着城市化进程的发展，北京市中心城建设用地不断扩张， 大量城市边缘区绿色空间被侵占，对城市生态环境造成极大影响。以 北京市中心城1992和2016年的遥感数据作为基础数据，对其用地转 换以及空间分布变化进行分析，运用InVEST模型评估土地利用变化 对中心城生境的影响，获取北京中心城生境质量和生境退化的空间分 布格局。研究表明：1992—2016年北京市中心城绿色空间用地绝大 多数转变为建设用地，除草地面积增加外，其他绿色空间用地均有所 减少；中心城高度生境和中度生境面积均缩小，一般生境面积显著增 加，到2016年轻度退化生境占总面积的80.5%。在“留白增绿”的 政策背景下，生境评价的结果为北京中心城绿色空间规划及城市森林 建设提供了重要的参考依据。     

Modeling the Economics of Biodiversity and Environmental Heterogeneity

It has long been recognized that major drivers of biodiversity loss include both the harvest of wild species and the conversion of habitat for productive purposes. Land that is converted may or may not be lost as habitat for many species. In some cases, monoculture production for example, land conversion reduces the number niches and hence the level of biodiversity. In other cases, it has the opposite effect. We address the problem of anthropogenic biodiversity change due to the effects of both harvest rates and land use decisions on landscape heterogeneity. If the optimal structure of the landscape is extremely homogeneous, forces of competitive exclusion will lead to a single surviving species. If it is extremely heterogeneous, multiple species will coexist, with each species exclusively dominating the patch type to which it is best suited. Where changes in biodiversity due to changes in landscape heterogeneity are not taken into account in land use decisions, they are external effects of those decisions. We identify measures of these effects.     

填海造地外部生态成本补偿的关键点及实证分析

针对填海造地的生态环境损失,文章探讨了生态成本补偿问题的几个关键点。文章认为,由于填海造地行为彻底改变了海洋资源的自然属性,并造成资源和生态环境损失,需要一种补偿来弥补填海造地的负外部性,补偿的主体是填海造地的开发者,补偿对象是海域的所有权方,补偿的标准应以被填海域资源和生态环境损失成本为依据,补偿的手段应为征收生态补偿金。文章以福建某填海造地工程为例,对补偿标准的计算进行实证分析,得出该项填海造地工程的外部生态成本为377.70元/m2,计算结果可为国家征收填海造地的生态补偿金提供决策依据,以实现填海造地的有偿化和有序化。     

天津市华明镇土地开发整理模式研究

天津市华明镇通过＂宅基地换房＂土地开发整理新模式在为中心城市提供了大量城市建设用地的同时,又提供了促进农村城镇化的建设资金。利用案例分析方法,对华明镇宅基地换房背景分析,分析了华明镇模式在农用土地流转、征地补偿、土地集约利用、产业结构优化、城镇规划以及城乡一体化等方面的现实和理论意义,研究认为华明镇模式是目前解决大城市地区农村城市化面临的土地和资金问题可供选择的模式之一。     

加快农村义务教育发展的财政政策思考

随着改革开放的进一步深化,中国的义务教育财政政策进行了重大调整,从而使农村义务教育取得了较好的成就,并积累了一定的经验,但仍存在学校间差距仍然较大、代课人员难以清退、义务教育债务化解难度较大等问题。应实行统筹城乡发展的义务教育财政体制,采取照顾代课人员的考录及补偿政策,中央财政建立激励机制对地方化解债务给予适当支持,促进义务教育的均衡发展。     

Spatial Management of Invasive Species: Pathways and Policy Options

In addressing the problem of invasive species, decision makers have a variety of options, each targeting different aspects as it evolves over time and space. We develop a 2-region bioeconomic model that includes several transmission pathways that spread the invader. Within each region, inspections, removal efforts, and sustainable land management practices, including habitat restoration and less damaging production activities, are available to the regulator. We investigate the implications of different transmission pathways and second-best policies on the control patterns and invasive populations. Second-best settings where certain controls are not available to the regulator result in large distortions on the optimal use of the land. Overall, we find that non-linear interactions between regions, pathways, and controls are significant determinants of the optimal management of invasive species.     

Conserving biodiversity with tradable permits under changing conservation costs and habitat restoration time lags

Tradable permits are a common environmental policy instrument that has recently been applied also to the conservation of biodiversity. Biodiversity conservation differs in many respects to the classical applications of tradable permits like emissions control. One particularity is that, even if the permit system maintains a constant total amount of species habitat, habitat turnover (the destruction of a habitat and restoration elsewhere) affects the ecosystem. Another particularity is that the restoration of habitats often takes much time, leading to time lags between the initiation of restoration activities and the time when restored habitat is available for trading. We use an agent-based model of a tradable permit market to study the influence of heterogeneous and dynamic conservation costs and habitat restoration time lags on key variables of the market, such as the costs incurred to the market participants and the amount of habitat turnover. Our results show that there may be trade-offs between these key variables. We also find that restoration time lags can lead to fluctuations in permit prices that reduce the efficiency of the permit market. We conclude that temporal lags deserve a careful analysis when implementing tradable permit systems for the preservation of natural habitats and biodiversity.     

Separability and aggregation of equivalence relations

We provide axiomatic characterizations of two natural families of rules for aggregating equivalence relations: the family of join aggregators and the family of meet aggregators. The central conditions in these characterizations are two separability axioms. Disjunctive separability, neutrality, and unanimity characterize the family of join aggregators. On the other hand, conjunctive separability and unanimity characterize the family of meet aggregators. We show another characterization of the family of meet aggregators using conjunctive separability and two Pareto axioms, Pareto⁺ and Pareto^?. If we drop Pareto^?, then conjunctive separability and Pareto⁺ characterize the family of meet aggregators along with a trivial aggregator.     

Optimal compensation for potential fatality

Cordes and Weisbrod have recently demonstrated that the requirement that the government actually compensate individuals adversely affected by public projects is likely to have serious resource allocation implications. We examine a rudimentary model of government discretionary behaviour subject to a compensation requirement in the presence of physical risks. Risk assessments are endogenous and asymmetrically held — features enabling analysis of the trade- offs between compensation and protection or information available to the government, and of the structure of compensation which motivates it to do what is objectively best for the individual. We show that, paradoxically, greater government discretion seems more likely to ensure the latter.     

Interspecies Management and Land Use Strategies to Protect Endangered Species

We consider an ecosystem management problem where managers can use habitat creation and predator removal to conserve an endangered species. Predator removal may become particularly important in the face of habitat loss, and ecosystem management strategies that ignore the influence of habitat are likely to be inefficient. Using a bioeconomic model, we show that the marginal impact of prey habitat on predators is a key factor in determining the substitutability or complementarity of habitat and removal controls. Applying the model to the case of the endangered Atlantic-Gaspésie Woodland Caribou (rangifer tarandus caribou), we find that the first-best strategy involves extensive caribou habitat protection and a large predator cull initially, and then substituting habitat investments for predator removal as both populations begin to recover, suggesting that habitat protection and predator removal are effectively substitute controls.     

Education for all. A welfare-improving course for Africa?

In this paper, we argue that the case for universal compulsory education for sub-Saharan Africa might have been overstated. We capture the African situation through a heterogeneous-agent model, in which high costs of education relative to income and the skill premium cause the economy to stagnate in a low steady state with minimal educational attainment. We calibrate the model to available data from the sub-Saharan African countries to study education policies. We find that a tax and in-kind subsidy scheme that effectively redistributes resources from households with lower ability children to those with higher ability children outperforms enrollment-maximizing policies such as the abolition of child labor and compulsory education.     

Applying tradable permits to biodiversity conservation: Effects of space-dependent conservation benefits and cost heterogeneity on habitat allocation

This paper is concerned with the cost-effective allocation of habitat for species under spatio-temporally heterogeneous economic development. To address the dynamic dimension of the problem we consider tradable development rights as the instrument of choice. A particular challenge in applying tradable development rights is that the conservation benefit of an individual habitat patch depends on its spatial relationship with other habitat patches and thus is an emergent rather than a fixed property. We analyse with a conceptual model the spatial and temporal dynamics of habitats in a region under a tradable development rights market that takes spatial interaction of habitats explicitly into account. In our analysis two different outcomes may emerge depending on the levels of spatial interaction and cost heterogeneity: an “ordered” structure where habitat patches are clustered in space and are stable over time, and a “disordered” structure where habitat patches are scattered in space and subject to high turnover of destruction and recreation. A high level of spatial interaction or a low level of cost heterogeneity favours an ordered structure while a low level of spatial interaction or a high level of cost heterogeneity favours a disordered structure.     

The value of ecosystem services provided by the U.S. National Wildlife Refuge System in the contiguous U.S.

Studies that demonstrate the economic value of the ecosystem services provided by public conservation lands can contribute to a more accurate appraisal of the benefit of these lands. The objective of this study was to estimate the economic value, in real (2004) dollars, of the ecosystem services provided by the U.S. National Wildlife Refuge System (Refuge System) in the contiguous U.S. In order to estimate this value, we determined the ecosystems present on the Refuge System in the contiguous 48 states, the proportion in which they are represented, and the dollar value of services provided by each. We used land cover classes as an approximation of ecosystems present in the Refuge System. In a geographic information system (GIS), we combined land cover geospatial data with a map of the Refuge System boundaries to calculate the number of acres for each refuge and land cover class within the Refuge System. We transferred values for the following ecosystem services: climate and atmospheric gas regulation; disturbance prevention; freshwater regulation and supply; waste assimilation and nutrient regulation; and habitat provision. We conducted a central tendency value transfer by transferring averaged values taken from primarily original site studies to the Refuge System based on the ecoregion in which each study site and refuge was located and the ecoregion's relative net primary productivity (NPP). NPP is a parameter used to quantify the net carbon absorption rate by living plants, and has been shown to be correlated with spatially fungible ecosystem services. The methodologies used in the site studies included direct market valuation, indirect market valuation and contingent valuation. We estimated the total value of ecosystem services provided by the Refuge System in the contiguous U.S. to be approximately $26.9 billion/year. This estimate is a first cut attempt to demonstrate that the value of the Refuge System likely exceeds the value derived purely from recreational activities. Due to limitations of current understanding, methods and data, there is a potentially large margin of error associated with the estimate.     

Why Doesn’t the Hong Kong Government Sell More Public Land?

Why doesn’t the Hong Kong government sell more of its enormous land holding to lower the city’s high housing price and increase the residents’ small living space? We answer the question in an overlapping generations framework. We show that while a rapid and complete privatization of government land is efficient in the absence of externalities; it is made politically difficult by a compensation gap, when the losses of current property owners are greater than the government revenue from land sales. We argue that the cross-country diversity of government land ownership owes to historical incidents in some countries (such as the U.S. in the 19th century) that allowed disposal of government land without filling the compensation gap and the absence of such incidents in others (such as Hong Kong).     

The value of ecosystem services provided by the U.S. National Wildlife Refuge System in the contiguous U.S.

Studies that demonstrate the economic value of the ecosystem services provided by public conservation lands can contribute to a more accurate appraisal of the benefit of these lands. The objective of this study was to estimate the economic value, in real (2004) dollars, of the ecosystem services provided by the U.S. National Wildlife Refuge System (Refuge System) in the contiguous U.S. In order to estimate this value, we determined the ecosystems present on the Refuge System in the contiguous 48 states, the proportion in which they are represented, and the dollar value of services provided by each. We used land cover classes as an approximation of ecosystems present in the Refuge System. In a geographic information system (GIS), we combined land cover geospatial data with a map of the Refuge System boundaries to calculate the number of acres for each refuge and land cover class within the Refuge System. We transferred values for the following ecosystem services: climate and atmospheric gas regulation; disturbance prevention; freshwater regulation and supply; waste assimilation and nutrient regulation; and habitat provision. We conducted a central tendency value transfer by transferring averaged values taken from primarily original site studies to the Refuge System based on the ecoregion in which each study site and refuge was located and the ecoregion's relative net primary productivity (NPP). NPP is a parameter used to quantify the net carbon absorption rate by living plants, and has been shown to be correlated with spatially fungible ecosystem services. The methodologies used in the site studies included direct market valuation, indirect market valuation and contingent valuation. We estimated the total value of ecosystem services provided by the Refuge System in the contiguous U.S. to be approximately $26.9 billion/year. This estimate is a first cut attempt to demonstrate that the value of the Refuge System likely exceeds the value derived purely from recreational activities. Due to limitations of current understanding, methods and data, there is a potentially large margin of error associated with the estimate.     

Cost-effective species conservation in exurban communities: A spatial analysis

Exurban areas have increasingly become zones of conflict as conservation and development compete for the same finite land resources. Conversion of natural areas to land dominated by human use results in loss, degradation, and fragmentation of wildlife habitat which often lead to species endangerment or even extinction. Recently, reserve site selection models have begun to integrate spatial attributes in order to design more compact and connected reserve networks that are thought to improve long-term species persistence. While these models are a good step forward to designing conservation reserve networks, they might not be adequate for use in exurban areas that consist of heterogeneous mosaics of land uses where habitat fragmentation already exists and not all parcels are available for preservation. This paper presents a species conservation framework that expands upon traditional reserve site selection models in three ways. First, because of the focus on exurban areas, the framework used here allows for land conversion within core habitat patches. Second, the framework provides a more robust assessment of connectivity among patches by accounting for land-use heterogeneity in the dispersal matrix. And third, the framework explicitly incorporates species population dynamics. We apply our conservation framework to the case of pond-breeding salamanders in an exurban community in Rhode Island, USA. Comparisons are made between the outcomes for uniform conservation policies and more flexible policies that accommodate ecological and economic heterogeneity. As expected, policies that offer more flexibility in the decision-making process are less costly in terms of foregone development. Conservation planners should consider core habitat patches, dispersal matrix, and spatial scale in their decision making. By not assessing the potential impact of dispersal barriers, reserve site selection models will result in conservation plans that may not protect species over the long term, particularly for species residing in highly fragmented landscapes such as those found in many exurban communities.     

THE COST OF LAND USE REGULATION VERSUS THE VALUE OF INDIVIDUAL EXEMPTION: OREGON BALLOT MEASURES 37 AND 49

This article presents an exploratory analysis of the effects of land use regulations on land values and land use patterns in a landscape near Eugene, Oregon. All land use regulations considered in this study, including exclusive farm use zoning, forest zoning, urban growth boundary designation, residential density zoning, commercial zoning, and industrial zoning, are found to affect land values and land use patterns both inside and outside of the designated zones. The framework is applied to measure the costs of the regulations versus the value of individual exemptions at the parcel level to illuminate the controversy surrounding Oregon Measures 37 and 49, which were passed to provide “just compensation” for “unfair regulatory burdens.” The cost of regulation is found to be lower than the value of an individual exemption for most regulations contested in the Measure 37 claims. However, governments tend to overregulate from the perspective of landowners. Although some land gained value under the six regulations and some lost value, the aggregate loss of land value was estimated to be several times larger than the gain. This does not necessarily mean that the governments overregulate from the perspective of society because land use regulations also generate public goods such as wildlife habitat and water quality protection. (JEL K11, R15, R52)     

Conserving metapopulations in human-altered landscapes at the urban–rural fringe

The conversion of natural areas to human-dominated land uses results in loss, degradation, and fragmentation of wildlife habitat which often lead to species endangerment and local extinction. The risk of endangerment may be particularly acute for species that exist as metapopulations in which viability of the species is contingent upon dispersal of individuals among local sub-populations. This paper uses an optimization framework to investigate the problem of conserving metapopulations residing in areas at the urban–rural fringe. We compare the optimal allocation of preservation to outcomes of four other policy alternatives including the reserve-site-selection option that fully preserves habitat patches while allowing full development of the intervening dispersal matrix. In general, the optimal allocation includes some amount of preservation in both habitat patches and dispersal matrix, with the level of protection typically greater in habitat patches. The reserve-site-selection conservation option is optimal in only a few cases. Heterogeneity in terms of land use and landscape structure adds complexity to the optimal solution such that no one policy works well across all land units and in situations where the landscape structure is skewed, full protection of some land units and full development of others becomes more common.     

征地区片农地价格的理论与现实的差距研究——以泰州市为例

随着我国经济的高速发展,越来越多的农用地被征收和征用为建设用地,因此征地的补偿对广大农民来说就显得至关重要。虽然国家已经取消了征地补偿的最高标准,并逐步推广了同地同价的征地区片综合地价,但与市场价格相比,还有很大的差距。本文通过理论与实证研究建立征地区片单元的单元分值与样点地价的关系模型,测算不同级别的区片价格,与现行标准的征地区片价进行比较,验证了目前的征地区片价是扭曲的,由此提出了相应的政策建议。