A dynamic approach to PES pricing and finance for interlinked ecosystem services: Watershed conservation and groundwater management

A theory of payment for ecosystem services (PES) pricing consistent with dynamic efficiency and sustainable income requires optimized shadow prices. Since ecosystem services are generally interdependent, this requires joint optimization across multiple resource stocks. We develop such a theory in the context of watershed conservation and groundwater extraction. The optimal program can be implemented with a decentralized system of ecosystem payments to private watershed landowners, financed by efficiency prices of groundwater set by a public utility. The theory is extended to cases where land is publicly owned, conservation instruments exhibit non-convexities on private land, or the size of a conservation project is exogenous. In these cases, conservation investment can be financed from benefit taxation of groundwater consumers. While volumetric conservation surcharges induce inefficient water use, a dynamic lump-sum tax finances investment without distorting incentives. Since the optimal level of conservation is generated as long as payments are correct at the margin, any surplus can be returned to consumers through appropriate block pricing. The present value gain in consumer surplus generated by the conservation-induced reduction in groundwater scarcity serves as a lower bound to the benefits of conservation without explicit measurement of other benefits such as recreation, biodiversity, and cultural values.     

Mountain-to-sea ecological-resource management: Forested watersheds,coastal aquifers,and groundwater dependent ecosystems

Improving the understanding of connections spanning from mountain to sea and integrating those connections into decision models have been increasingly recognized as key to effective coastal resource management. In this paper, we aim to improve our understanding of the relative importance of linkages between a forested watershed, a coastal groundwater aquifer, and a nearshore marine groundwater-dependent ecosystem (GDE) using a dynamic groundwater optimization framework and simple ecosystem equations. Data from the Kīholo aquifer on the Kona Coast of Hawai‘i Island are used to numerically illustrate optimal joint management strategies and test the sensitivity of those strategies to variations in physical and behavioral parameter values. We find that for a plausible range of watershed management costs, protecting part of the recharge capture area is always optimal. Without watershed protection, maintaining a safe minimum standard growth rate for a GDE-dependent marine indicator species, reduces net present value non-trivially, but optimal investment in watershed conservation offsets that potential reduction by 75 %. In general, we find that optimal watershed management and groundwater pumping are most sensitive to changes in water demand growth and parameters that describe nearshore salinity.     

由单一走向多样：平原农业区生物多样性 保护的规划途径——以辽宁省黑山县为例

平原农业区的生产和土地利用方式严重影响区域的 生物多样性,利用融合多学科的景观空间规划构建有效的评价 方法和格局优化模式以实现多样化的生境保护和恢复,提升生 物多样性具有重要的作用。以辽宁省黑山县为例,首先梳理了 平原农业区对于生物多样性威胁的机制和研究的框架;其次识 别平原农业区的特殊生境类型,使用景观格局指数和InVEST 模型的生境质量评价构建多尺度生境质量评价机制;同时使用 基于图论和电路理论的Linkage Mapper软件,识别和分级 空间中的重要生态源地、潜在廊道及廊道上的关键夹点区域。 结果显示,农业景观中空间异质性和连接性影响生物多样性; 研究区有主要生境23类,整体生境质量较差,农田面积较大 是造成该问题的主要原因;识别出核心斑块33个,重要廊道 34条,通过与卫星图比照,廊道位置与线性生境重合;关键 夹点区域位于靠近农村居民点的自然生境上,故营造人类干扰 与生态平衡农村居住区是空间规划的重点;同时根据以上研究 提出了多尺度的空间规划途径,为平原农业区生境优化和生物 多样性保护提供了一定的理论参考。     

Climate policy vs. agricultural productivity shocks in a dynamic computable general equilibrium (CGE) modeling framework: The case of a developing economy

The main objective of this paper is to compare the cost of climate policy consistent with the 2 °C global warming target (Paris Agreement target) with the cost of climate change induced agricultural productivity shocks, using a recursive dynamic CGE model for India. The social cost of carbon, in terms of loss in agriculture sector, is estimated to be about 2 percent of GDP, at zero rate of discount, under conservative forecasts of fall in agricultural productivity. In comparison, the cost of climate policy consistent with the Paris Agreement target of 2 °C is about 1 percent of GDP. Thus, there is a strong case for the adoption of ambitious climate policy in India, provided other countries also adhere to the same. Besides, revenues generated from the carbon tax and emission allowance could be a means to support the development and adoption of new energy and agricultural technologies, to increase social sector expenditure and to reduce abatement costs.     

Groundwater management under heterogeneous land tenure arrangements

We develop a groundwater extraction model that considers the Marshallian inefficiency associated with sharecropping and use data from Pakistan to simulate the impact of an open access regime and of optimal management on groundwater extractions, the state of the aquifer, and annual net benefits through time. We also evaluate a price instrument as a mechanism of inducing optimal extractions. Under both open access and optimal management, we observe notable differences in groundwater extractions and the water table level between the tenure model (which considers the behavior of both owner cultivators and sharecroppers) and the baseline model (which includes the behavior of only owner cultivators). We also find a modest difference in the aggregate net benefits generated by the two models. The results offer new insights—vis-à-vis land tenure heterogeneity—into the evaluation of more effective policies for groundwater management and aquifer sustainability.     

“A note on soil depth,failing markets and agricultural pricing”: Comment

Bulte and van Soest [Bulte, E., van Soest, D. 1999. A note on soil depth, failing markets and agricultural pricing. Journal of Development Economics 58, 245-254.] argue that higher agricultural output prices result in greater soil conservation when labor markets function well but have ambiguous effects when labor markets are absent. The latter result is not attributable to labor market failure but rather occurs whenever labor supply is less than perfectly elastic. Consistent with the more general model presented here, empirical evidence from a number of developing countries suggests that well-functioning labor markets are associated with decreases in investment in soils.     

Depletion,climate, and the incremental value of groundwater

Groundwater provides vital inputs to crop production and contributes to rural economies throughout the world. Research on the economic benefits associated with groundwater resources has typically focused on the impacts of groundwater availability on the profitability of agricultural production or on the non-market benefits associated with groundwater quality for human consumption. In this research, we use stated-preference methods to investigate the total economic value to agricultural producers of an increase in groundwater availability in the Ogallala Aquifer region. The contingent valuation method allows for estimation of values beyond agricultural profitability, including non-market values such as the ability to leave additional groundwater to future generations. We find a median willingness to pay (WTP) for an additional 100 gallons per minute of well capacity of $77 per well, and that this estimate depends strongly on current well capacity and climate conditions. For counties in hotter and drier regions of the aquifer with low well capacity, median WTP is significantly higher. These results are then used in conjunction with projections of future climate and groundwater availability to generate predicted changes in the WTP for additional groundwater across the aquifer. This research provides important feedback on how the benefits of additional groundwater availability are predicted to change as groundwater resources are diminished in a changing climate.     

Groundwater and ecosystems damages: Questioning the Gisser-Sánchez effect

Gisser and Sánchez (1980a) state the conditions under which welfare gains from policy intervention are negligible in aquifer management, when compared with non-regulation or “free market” outcomes. This is the so-called Gisser-Sánchez effect (GSE), which has been supported by the ensuing literature during recent decades. The GSE requires a number of assumptions, among which is the disregard for aquatic ecosystems linked and dependent on aquifer systems. The depletion of aquifer systems in arid and semiarid regions worldwide is causing acute water scarcity and quality degradation, and leading to extensive ecosystem damages. This study shows that by including environmental damages into the analytical model, results can change substantially. The analysis highlights both theoretically and empirically the importance of policies in groundwater management, as well as the potential role for stakeholders' cooperation. The empirical application deals with two large aquifers in Spain, the Western La Mancha aquifer which is grossly mismanaged, and the Eastern La Mancha aquifer, which is moving towards sustainable management. Western and Eastern La Mancha aquifers illustrate that policies and institutions are essential to avoid the current global aquifer mismanagement.     

Sensitive products in the Doha negotiations: The case of European and Japanese market access

Given the highly concentrated distribution of agricultural protection, allowing in the negotiations too many exceptions through sensitive products puts at risk the objectives of World Trade Organization. This issue is difficult to analyze with the commonly used applied trade models, because they represent trade flows at an aggregate level, while sensitive products are picked at the product level and their protection, under the form of tariff-rate quotas, is contingent on the level of imports. This paper assesses the effect of these exceptions, based on the case of agricultural trade protection in Europe and Japan, two countries where tariff dismantling in the agricultural sector is a particularly sensitive issue. Since agricultural border protection is heterogeneous, we avoid aggregation bias by extending a multi-country computable general equilibrium model to the product level. This allows us to represent trade policies explicitly and to account for their interdependencies. The results suggest that consideration of sensitive products strongly limits the potential gains from a possible agriculture agreement at Doha. Moreover, there is no aggregate trade-off between decreasing tariffs and increasing/opening quotas. To achieve “substantial” market access improvements in the agricultural sector, the objective should be most favored nation tariff reduction.     

The effects of macroeconomic factors on South African agriculture

Significant research efforts have been devoted to understanding the effects of macroeconomic factors on the agriculture sector. Analysing the sources of volatility in the industry is critical for designing appropriate policies to stabilize agricultural markets, reduce poverty and increase economic growth. Agriculture is a competitive sector with prices that are more flexible than those in nonagricultural sectors. This article uses annual data over the 1957–2004 period and a vector error-correction model in investigating the dynamic effects of exchange rates, money supply and other macroeconomic variables on the agricultural sector in South Africa. Overall, real exchange rates, interest rates, inflation and money supply (M3) shocks have significant and persistent impacts on agricultural output, prices received by farmers and farm input prices. M3 and interest rate shocks tend to put agriculture in a cost-price squeeze. Agricultural price movements are a source of macroeconomic instability in the country. Real exchange rate shocks shift relative prices in favour of agriculture in the long-run, thereby, boosting farm incomes and accelerating poverty reduction in the country.     

The Intersectoral Terms of Trade and Their Impact on Urbanisation in China

The historical experience of developed countries shows that the economic development process and accompanying urbanisation represent a structural transformation from an economy dominated by agriculture to one dominated by non-agricultural activities. Therefore it is generally believed that the agricultural sector needs to make a net transfer of resources, both capital and labour, to other sectors in the processes of economic transformation and urbanisation. However, the process of urbanisation in a socialist economy can be negatively affected by its pattern of resource generation. On the basis of an analysis of the 'scissors' pricing mechanism to which the state had recourse for financing its industrialisation, this article argues that this kind of resource transfer did not necessarily favour a high rate of urban employment and urbanisation, regardless of the magnitude of the seizure of resources from the agricultural sector.     

Social contracts,markets and efficiency: Groundwater irrigation in North India

This paper uses primary data to analyze the institutions and informal markets that govern groundwater allocation in a sugarcane-cultivating village in North India. We find that, in contrast to earlier literature, the observed water trades result in efficient water allocation across farms. We interpret this and other stylized facts in terms of a social contract using a simple bargaining model with limited inter-player transfers. Poor functioning of the power sector leads to reduced pumping and a water supply constraint. Simulations show that power supply reform can significantly increase farm yields, and be financed out of increased farm profits.     

Renewable resource management with stock externalities: Coastal aquifers and submarine groundwater discharge

We model coastal groundwater management and its effects on submarine groundwater discharge, nearshore marine water quality, and marine biota. Incorporating the stock externality effects on nearshore resources increases the optimal sustainable steady-state levels of both the aquifer head and the stock of a keystone native algae species. Numerical simulations are illustrated using data from the Kuki’o region on the Island of Hawaii. Two different approaches for incorporating the nearshore resource are examined. Including algae's market value in the objective function results in only slightly lower rates of groundwater extraction. When a minimum constraint is placed on the stock of the keystone species, however, greater conservation may be indicated. The constraint also results in non-monotonic paths of water extraction, head level, and marginal opportunity cost of water in the optimal solution.     

The Impact of Sector-Specific and Economy-Wide Policy Reforms on the Agricultural Sector in Brazil: 1980–98

This article analyzes the impact of policy reforms and changing macroeconomic conditions on the Brazilian agricultural sector. It stresses four issues: events outside of agriculture were central to the performance of the sector and to the timing and sequence of policy reform; reform involved far more than trade liberalization; the impact of reform on input markets and productivity was key for understanding the period; and policy reform had a highly differentiated impact on the sector. As a result of the reforms, agriculture became the most dynamic sector of the Brazilian economy in the 1990s. Policies still in need of reform are identified. (JEL O13 , Q18 )     

Effects of instantaneous groundwater availability on irrigated agriculture and implications for aquifer management

Groundwater is an important input for agricultural production in many parts of the world. Aquifer depletion has been shown to affect the rate that groundwater can be extracted from an aquifer. In this paper, we develop an analytical framework that accounts explicitly for the effects of limited instantaneous groundwater extraction rate (well capacity) on a producer's irrigation decisions. We show that limited well capacities can affect the producer’s groundwater use and profit. We draw three important insights from these findings. First, we demonstrate that the price elasticity of demand for groundwater is higher for lower well capacities. Second, farmers’ irrigation decisions are non-monotonic with respect to well capacity and climate conditions. Under a drier climate, producers with greater well capacities increase their groundwater use, and producers with lower well capacities reduce their water use. Third, through numerical analysis, we show that considering spatial heterogeneity in well capacities is important for estimating the cost-effectiveness and distributional impacts of groundwater management policies. Our results shed new light on the importance of extraction capacity for groundwater management policies and the potential impacts of climate change on agricultural production.     

Hydro-economic river basin modelling: The application of a holistic surface-groundwater model to assess opportunity costs of water use in Spain

Combined hydro-economic models of river basins are fundamental tools for assessing management and infrastructure strategies to improve the economic efficiency of water use in a context of competition over scarce water resources. Integrated hydro-economic models have to be capable to properly reproduce the physical behavior of the system, with a realistic representation of the different surface and groundwater resources, including their interaction, and the spatial and temporal variability of resource availability. On the other hand, such models must incorporate the value of water for different urban, agricultural and industrial uses and users. Economic values for water use are defined according to the marginal residual value of water for production (for agricultural and industrial uses) or the aggregated willingness-to-pay (WTP) for urban supply and other final water uses. In this paper, we present a systematic approach to estimate the marginal economic value of surface and groundwater resources at different locations within a complex water resources system. Based on a holistic conjunctive optimization model applied to the Adra river system in Spain we asses the total and marginal opportunity costs of capacity and operation constraints, including the opportunity cost of imposing environmental constraints on water use as foreseen in future Spanish water policy following the implementation of the European Water Framework Directive. The resulting opportunity costs provide important information to water managers about economic inefficiencies of current water allocation policy or infrastructure design, and about the resource opportunity costs to be considered in the design of efficient pricing policies in regions with water scarcity issues.     

淮北平原农用地下水应急水源建设研究

淮北平原是安徽省粮食主产区,干旱是影响该地区农业生产的主要气象因素,制约着该地区的农业稳产增产。由于降水、地表水时空分布不均,难以有效应对重特大气象干旱;而埋藏浅、就地可采、资源丰富的浅层地下水则是最好的应急水源。文章通过分析淮北平原浅层地下水的赋存条件和资源特征,提出了浅层地下水库的理念,并着重强调了浅层地下水库的调节功能。根据农用地下水的开采现状,以及应对气象干旱的农业供水要求,有针对性地提出了浅层地下水开发利用的对策与建议。     

Analyzing the effect of advanced agriculture development policy

This paper broadens the scope of current theoretical studies, divides rural agriculture into two sectors—advanced and traditional, and takes into consideration the land factor and the urban informal sector. Under the assumption that wages in the advanced agricultural sector are higher than in the traditional agricultural sector, this paper analyzes the effect of policies to promote advanced agricultural development with the comparative static method. The main conclusions of this paper are: wage subsidization of the advanced agricultural sector, in addition to having the same economic impact as interest subsidies on the advanced agricultural sector, could also increase the land employment in the advanced agricultural sector and reduce that in the traditional agricultural sector. Therefore, the effect of wage subsidizing policies is stronger than that of interest subsidies, while land rent subsidies for the advanced agricultural sector have the same economic effect as wage subsidies.     

Mitigating Negative Water Quality and Quality Externalities by Joint Management of Adjacent Aquifiers

Groundwater basins are usually separated into aquifers that are hydrologically interrelated. This interrelation may take the form of water movement from one aquifer to another. When differentials in water quality exist, pumping from one of the aquifers can cause water movement that may be associated with degradation of its quality. A management policy that considers this interrelation may be preferable to an independent management of each aquifer. This paper develops a dynamic optimal control model to evaluate joint versus independent management. The optimal joint pumping management, in which two adjacent aquifers of different water qualities are interrelated, is analyzed and compared to independent aquifer pumping, and the situations where joint management is not required are identified. Policy implications are then derived and discussed. Finally, the theoretical model is applied to a case of interrelated aquifers in southern Israel. The empirical model identifies conditions (interest rate, agricultural fresh water supply rainfall recharge, price of surface water, drinking water quality standards) under which a joint policy is preferable. The empirical results confirm the theoretical ones.     

A general equilibrium analysis of production subsidy in a Harris-Todaro developing economy: an application to India

Since 1950s India has advocated import substituting industrialization policies to promote its manufacturing sector. The end result was creation of a dual economy: highly favored manufacturing sector with high and rigid wages and neglected agricultural sector with low wages and poverty. Because of the higher wages in the manufacturing sector, the rural laborers migrate to the urban sector, a typical characteristic of the Harris-Todaro developing economy. Realizing this crisis, the Indian government recently initiated policies to boost agricultural production to curb the labor migration and improve the welfare of the rural population. In this study, we develop a computable general equilibrium (CGE) model for India by incorporating Harris-Todaro economic characteristics of unemployment, labor migration, farm dependant population, and labor-intensive agriculture. We use the model to analyze the effects of agricultural production subsidy policies on employment, factor price, output price, output levels, and welfare in agricultural and manufacturing sectors. Our findings show that agricultural production subsidy increases agricultural production, reduces unemployment, raises the wage rate in the agriculture sector, augments the consumption among the rural and urban households, and increases the rental rate for capital in agricultural sector.