A general equilibrium analysis of conjunctive ground and surface water use with an application to Morocco

Groundwater resources (GW) account for nearly 30% of the world's sustainable water supplies. Yet, this resource, which is fraught with externalities, has largely been left unregulated. The economic literature on GW is predominantly of a partial equilibrium type. We analyze GW regulation in a general equilibrium setting, focusing on the stabilization value of GW under natural (drought) and economic (rural–urban water transfer) shocks. A general equilibrium approach allows evaluating direct and indirect effects of GW regulation on agriculture and nonagriculture sectors and extends the scope for water policy. The analysis is applied to Morocco by extending an existing computable general equilibrium (CGE) model to include ground and surface water (SW) resources. We study effects of (i) an increase in GW extraction cost (e.g., as a result of prolonged extraction beyond natural recharge that lowers the aquifer's water table), (ii) a transfer of SW from rural (irrigation) to urban (domestic) use, and (iii) a reduction of water availability due to severe drought. We estimate the value of GW and assess the direct (partial equilibrium) and indirect (general equilibrium) impacts. We find that GW plays a critical role in mitigating the negative effects of these types of shocks.     

The Impact of an EU–US Transatlantic Trade and Investment Partnership Agreement on Biofuel and Feedstock Markets

We assess the impact of a potential TTIP bilateral free trade agreement on the EU and US bio‐economies (feedstock, biofuels, by‐products, and related competing crops) and major trade partners in these markets. The analysis develops a multi‐market model that incorporates bilateral trade flows (US to EU, EU to US, and similarly with third countries) and is calibrated to the OECD‐FAO baseline for 2013–2022 to account for recent policy decisions. The major policy reforms from a TTIP involve tariff and TRQ liberalisation and their direct contractionary impact on US sugar supply, EU biofuel production, and indirect negative effect on US high fructose corn syrup (HFCS) production. EU sugar and isoglucose production expand along with US ethanol and biodiesel and oilseed crushing. EU sugar would flow to the US, US biofuels and vegetable oil to the EU. We further quantify non‐tariff measures (NTM) affecting these trade flows between the EU and the US. EU oilseed production contracts, and EU crushing expands with improving crushing margins following reduced NTM frictions. Our analysis reveals limited net welfare gains with most net benefits reaped by Brazil and not the two trading partners of the TTIP.     

Food subsidies and market interdependence: the case of the Moroccan soft wheat subsidy

Among the several propositions advanced to explain the rising cost of subsidizing soft wheat production and consumption in Morocco are the indirect effects emanating from related markets, namely the hard wheat and barley markets. A three-sector supply-demand model, described in this paper, was used to estimate the direct and indirect (induced) effects on government cost of changes in the soft wheat subsidy. The results show that virtually all the indirect effects come from the soft wheat market itself. The indirect effects emanating from the related markets are negligible.     

Leveling the field for biofuels: comparing the economic and environmental impacts of biofuel and other export crops in Malawi

Biofuels often raise the specter of food insecurity, water resource depletion, and greenhouse gas emissions from land clearing. These concerns underpin the “sustainability criteria” governing access to European biofuel markets. However, it is unclear if producing biofuels in low‐income countries does exacerbate poverty and food insecurity, and moreover, whether the sustainability criteria should apply to all agricultural exports entering European markets. We develop an integrated modeling framework to simultaneously assess the economic and environmental impacts of producing biofuels in Malawi. We incorporate the effects of land use change on crop water use, and the opportunity costs of using scarce resources for biofuels instead of other crops. We find that biofuel production reduces poverty and food insecurity by raising household incomes. Irrigated outgrower schemes, rather than estate farms, lead to better economic outcomes, fewer emissions, and similar water requirements. Nevertheless, to gain access to European markets, Malawi would need to reduce emissions from ethanol plants. We find that biofuels’ economic and emissions outcomes are generally preferable to tobacco or soybeans. We conclude that the sustainability criteria encourage more sustainable biofuel production in countries like Malawi, but are perhaps overly biased against biofuels since other export crops raise similar concerns about food security and environmental impacts.     

Geographical downscaling of outputs provided by an economic farm model calibrated at the regional level

There is a strong need for accurate and spatially referenced information regarding policy making and model linkage. This need has been expressed by land users, and policy and decision makers in order to estimate both spatially and locally the impacts of European policy (like the Common Agricultural Policy) and/or global changes on farm-groups. These entities are defined according to variables such as altitude, economic size and type of farming (referring to land uses). European farm-groups are provided through the Farm Accountancy Data Network (FADN) as statistical information delivered at regional level. The aim of the study is to map locally farm-group probabilities within each region. The mapping of the farm-groups is done in two steps: (1) by mapping locally the co-variables associated to the farm-groups, i.e. altitude and land uses; (2) by using regional FADN data as a priori knowledge for transforming land uses and altitude information into farm-groups location probabilities within each region. The downscaling process focuses on the land use mapping since land use data are originally point information located every 18 km. Interpolation of land use data is done at 100 m by using co-variables like land cover, altitude, climate and soil data which are continuous layers usually provided at fine resolution. Once the farm-groups are mapped, European Policy and global changes scenarios are run through an agro-economic model for assessing environmental impacts locally.     

Land-property markets and planning: A special case

Land use policy often intervenes in land-property markets. This raises a question that may have critical implications for land use policy: are these normal markets? This paper addresses that question: are land and property ordinary market goods, or do they lack some of the preconditions necessary for markets to work properly? We find that land-property has limited substitutability, due to the critical factor of location; qualified by location, land is limited and sometimes unique. These attributes make land and property investment assets risking speculation, warranting public intervention to mitigate negative social consequences. Land-property markets need market or administrative support to work, which planning provides through public and private agents. The paper reviews the different forms of planning and development control in land-property markets.     

Evaluating the Market and Welfare Impacts of Agricultural Policies in Developed Countries: Comparison of Partial and General Equilibrium Measures

We revisit the question of choosing partial equilibrium or general equilibrium modeling in applied policy analysis in the context of evaluating the effects of a complete phase-out of the Common Agricultural Policy (CAP) of the European Union. We compare the results of three models—two three-sector general equilibrium models (one with an additional major distortion in the nonagricultural sector) and a two-sector partial equilibrium model. We find that the market effects of a complete phase-out of the CAP are quite comparable across these models. On the other hand, the measured welfare impacts may depend on the modeling choice.     

Output and input bias effects of U.S. direct payments

This study examines the national effect of U.S. direct payments on the extent and direction of biased technical change on U.S. agriculture. We also assess the economic significance of the estimated bias effects for economic policy modeling endeavors involving a reduction of domestic support payments. A two outputs (livestock and crops) and four inputs (labor, capital, land, and material) translog cost function was estimated from national time series (1948–2011) data. Results indicate that payments do not induce output‐biased technical change. We do find evidence of Hicksian bias that is land using and material input saving attributable to support payments. Global computable general equilibrium simulations suggest that price and output effects of discontinuing direct payments are 1/4 to 1/3 the size once the bias effects are incorporated.     

The impact of decoupled payments on U.S. cropland values

An extensive literature has shown that various farm programs may influence the value of farmland, but other studies have not examined the cropland price effects of direct, or decoupled, payments separate from countercyclical payments. This study uses nationally representative confidential field‐level panel data with farmer‐reported per‐acre land values. We analyze the impact of decoupled and other farm program payments on farmland values. Using a fixed effects model and controlling for various factors that influence farmland values, we find that an additional dollar of decoupled payments has a large and statistically significant impact on farmland values of about $18 per acre. These results are comparable with similar studies undertaken in Europe.     

土地利用对碳排放影响的作用机制和传导路径分析 ——基于结构方程模型的实证检验

研究目的：探索土地利用对碳排放影响的作用机制和传导路径,为制定土地调控碳减排政策体系提供科学依据,服务于碳中和目标。研究方法：理论框架构建法与结构方程模型相结合。研究结果：（1）农地非农化、土地出让市场化和土地开发强度是作为土地利用对碳排放影响的有效观测变量,我国省际层面土地利用对碳排放影响的总效应、直接效应和间接效应均表现为促进作用,总效应表现为土地利用水平提升1个单位,将促进碳排放增加0.159个标准单位,间接效应明显大于直接效应。（2）土地利用通过城市化、产业结构和经济增长三条路径对碳排放产生间接影响,其中,通过城市化和经济增长对碳排放表现为促进效应,影响大小分别为0.173和0.058个标准单位,通过产业结构对碳排放表现为抑制效应,影响大小为0.101个标准单位。研究结论：建立土地调控碳减排政策体系是推动碳中和目标实现的一项可行的重要手段,一方面可通过国土空间优化、生态红线划定和自然保护地整合等手段减少土地利用对碳排放的直接影响,另一方面可通过调控土地利用方式、规模、强度、结构等减少土地利用对碳排放的间接促进影响,激发土地利用的正向连锁效应。     

Assessing CAP Reform: Sensitivity of Modelling Decoupled Policies

The European Union reformed farm policy in June 2003 towards the decoupling of farm income support instruments. Available impact studies find that this reform reduces production incentives substantially for beef and to a lesser extent for arable crops. However, these studies assume that the previous reform, under Agenda 2000, already decoupled arable crop direct payments to a considerable extent, while beef premiums were linked more closely to production. Our main objective in this paper is to test the sensitivity of these results to this questionable modelling of Agenda 2000 direct payments, which neglects eligibility rules and land market imperfections. Our analysis reveals that the effects of the reform on both arable crop and beef production are always negative, however the Agenda 2000 direct payments are modelled. On the other hand, we show that, when the eligibility rules and land market imperfections are acknowledged, the production reducing effects may be much larger for arable crops than for beef. Policy implications of these results are noted.     

Agent‐based Modelling of Climate Adaptation and Mitigation Options in Agriculture

Computer simulation models can provide valuable insights for climate‐related analysis and help streamline policy interventions for improved adaptation and mitigation in agriculture. Computable general equilibrium (CGE) and partial equilibrium (PE) models are currently being expanded to include land‐use change and energy markets so that the effects of various policy measures on agricultural production can be assessed. Agent‐based modelling (ABM) or multi‐agent systems (MAS) have been suggested as a complementary tool for assessing farmer responses to climate change in agriculture and how these are affected by policies. MAS applied to agricultural systems draw on techniques used for Recursive Farm Programming, but include models of all individual farms, their spatial interactions and the natural environment. In this article, we discuss the specific insights MAS provide for developing robust policies and land‐use strategies in response to climate change. We show that MAS are well‐suited for uncertainty analysis and can thereby complement existing simulation approaches to advance the understanding and implementation of effective climate‐related policies in agriculture.     

Economic and environmental effects of decoupled agricultural support in the EU

This article reports findings from a simulation model representing the European farming system disaggregated at different scales. This modeling experiment explores the effects of various decoupling options associated with the 2003 European agreement on gross margins, land use, shadow cost of land, and greenhouse gas emissions. Our results show increases in the farmers’ gross margins when decoupled support is maintained equal to the amount of direct aid previously attributed to agricultural production, assuming unchanged prices. Land used for pasture increases at the expense of land used for cereals and protein crops. The extent to which these effects materialize depends on the policy options selected by Member States when implementing the Luxembourg agreement. When they opt for some recoupling of support, adverse net economic impacts occur for producers. Regional differences in impacts are more pronounced than the analysis aggregated at European and national scales suggests. This highlights the need for further work based on geostatistical downscaling.     

Price formation in the German biodiesel supply chain: a Markov‐switching vector error‐correction modeling approach

Changing linkages between agricultural and energy markets have attracted considerable attention in research and policy discussions during recent years. As one of the largest biofuel markets worldwide, the German biodiesel market is of particular interest. It has grown rapidly since the beginning of the new millennium, with this growth being driven mainly by political interventions. Vertical price transmission channels along the biodiesel supply chain are analyzed in this study. We examine the relationship between diesel and biodiesel prices, and between rapeseed oil, soy oil, and biodiesel prices between 2002 and 2008. Due to pronounced changes in market conditions and the policy framework, a regime‐dependent Markov‐switching vector error‐correction model is used. The regimes are characterized by markedly different price adjustment behaviors. Before 2005 and from late 2007 onward, a regime characterized by the strong orientation of biodiesel prices toward diesel prices dominates. Between 2005 and 2007, biodiesel and rapeseed oil prices are mutually interdependent. Frequent switches between the regimes of the price dynamics during this period indicate a high extent of uncertainty and instability in the market.     

Credit Market Imperfections and the Distribution of Policy Rents

This article shows that credit market imperfections have important implications for the distribution of policy rents. In a model with land as fixed factor and credit market imperfections, when an area payment is given, land rents go up by more than the subsidy. On aggregate farms may lose from the subsidy. The results depend on the extent to which subsidies have direct and indirect effects on the credit constraints, on whether farms rent or own land, and on farm heterogeneity.     

近年来中国土地政策调控效果评价

研究目的：从直接效应和间接效应两个层面对近年来土地政策参与宏观调控的效果进行测度和评价。研究方法：文献资料法、因果分析法和统计推断法。研究结果：近年来土地宏观调控取得显著成效,基本达到预期的政策目标。研究结论：今后应进一步调整和完善土地宏观调控政策,把促进就业和人口城市化纳入土地宏观调控政策的目标控制体系。     

Urban encroachment,forest regrowth and land-use institutions: Does zoning matter?

As concern grows regarding urban sprawl and forest and agricultural land preservation, the effectiveness of land-use policies in shaping land-use change warrants further study. We evaluate the impact of county-level zoning laws, the most predominant land use policy in the USA, and land rents on the relative amounts of forest, agricultural, and developed land, while controlling for demographic information and taxation rates. Over the past decades, southern Indiana has experienced forest regrowth on private lands, but this regrowth has declined in recent years with increased conversion of open space for urban residential development. We develop a model of land-use shares in 40 southern Indiana counties based on the net benefits to agriculture, forestland, and urban uses using a maximum likelihood estimation of a Dirichlet distribution. We find agricultural land rent and indicators of land productivity are the most important predictors of the proportion of agriculture and urban uses. Forest use is better explained by shifting regional economic structure and hilly terrain. Counties with a greater proportion of their work force in the service sectors have a greater proportion of land forested. Finally, to some extent zoning may protect agricultural land in the region, although land rents, land characteristics, and population are strong predictors of the ratio of agriculture to urban use.     

The iLUC dilemma: How to deal with indirect land use changes when governing energy crops?

Due to land use effects, bioenergy use may cause adverse effects on biodiversity, soil and water and may even fail to guarantee a GHG emissions reduction compared to fossil fuel use. Accounting methodologies and policy instruments were elaborated to prevent these effects, but there is still no sound and consensual methodology to take into account indirect land use change that substantially contributes to GHG emissions as well as a loss of biodiversity. While the iLUC hypothesis, that is the potentiality of adverse effects arising from indirect land use change related to biomass cultivation, is hardly subject to dispute, the quantification of these effects and especially their policy implications are however contentious. Hence, bioenergy policies worldwide face a dilemma: Neglecting iLUC effects that do in fact exist or taking them into account although no sound methodology is available? The article covers the current state of the discussion and also analyses the approaches developed for taking indirect land use change into account. Assessment criteria for coping with the iLUC dilemma are developed and policy recommendations are derived from that.     

Global market shocks and poverty in Vietnam: the case of rice

World food prices have experienced dramatic increases in recent years. These “shocks” affect food importers and exporters alike. Vietnam is a major exporter of rice, and rice is also a key item in domestic production, employment, and consumption. Accordingly, rice price shocks from the world market have general equilibrium impacts and as such, their implications for household welfare are not known ex ante. In this article, we present a framework for understanding the direct and indirect welfare effects of a global market shock of this kind. We quantify transmission of the shock from global indicator prices to domestic markets. Then we use an applied general equilibrium model to simulate the economic effects of the price changes. A recursive mapping to a nationally representative household living standards survey permits us to identify in detail the ceteris paribus effects of the shock on household incomes and welfare. In this analysis, interregional and intersectoral labor market adjustments emerge as key channels transmitting the effects of global price shocks across sectors and among households.