Browsing by Person "Dabbert, Stephan"

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Agro-economic policy analysis with the regional production model ACRE : a case study for Baden-Wuerttemberg
(2011) Henseler, Martin; Dabbert, Stephan
Since its introduction the Common Agricultural Policy (CAP) of the European Union (EU) has undergone several reforms in order to adapt policy instruments and enable the agricultural sector to fulfil multiple functions with respect to economic, supply and environmental objectives. In the German federal state Baden-Wuerttemberg agricultural production is characterized by regional heterogeneity. Therefore it is important to estimate the impacts resulting from changes in the CAP at a detailed regional level. In this study the agricultural policy model ACRE (Agro-eConomic pRoduction model at rEgional level) has been used to simulate different policy scenarios and to analyze regional economic, production and environmental impacts. In particular the study aims to address the following research questions: What are the regional impacts of different policy measures in the German federal state Baden-Wuerttemberg with respect to economic, production and environmental objectives? How suitable are the simulated policy measures for achieving the policy objectives of the CAP 2003 reform, as well as the objectives of subsidy reduction, promotion of energy crop production, reduction of environmental pollution and promotion of agro-environmental measures? How suitable is the regional supply model ACRE as a tool for policy analysis and policy decision support? In order to address the research questions, ACRE has been updated, adapted and extended to simulate agricultural production in the federal state Baden-Wuerttemberg at NUTS3 level. The policy scenarios simulated in this study are defined to cover recent discussions on the future development of the CAP and their results are analysed according to a regional framework for NUTS3 counties, farm types and the complete model region. The simulation of the reference year (REF) implies the policy reform Agenda 2000 in the simulation year 2000. Thus, REF represents the observed situation of regional agricultural production on whose statistical data ACRE is calibrated. The scenario CAP2003 simulates the policy measures of the CAP 2003 reform in the simulation year 2015. Assumptions of increased yields and prices as well as harmonized direct payments for arable land and grassland result in an increase in income as well as in an increase of subsidy volume. In the entire model region Baden-Wuerttemberg cereal production increases while the production of fattening bulls and pigs decreases. Increases in crop production intensity result in an increase in environmental pollution. The scenario CAP2003 is used as the baseline scenario to compare the results of simulated policy scenarios which are delineated in the following paragraphs only with the most important results for the complete model region Baden-Wuerttemberg. In two subsidy reduction scenarios the simulated policy instruments aim to reduce subsidy volume by reducing Pillar 1 payments by 60% and by shifting 70% of the money from Pillar 1 to Pillar 2 respectively. Both scenarios result in the positive impact of a decrease in subsidy volume, but show a negative impact, especially an increase of abandoned land. In two energy crop scenarios the production of energy maize is simulated under the assumption that different situations in energy policy and energy markets result in different competitiveness between production of energy maize and food. In both scenarios energy crop production partially replaces cereal production, although the extent varies according to the high or small level of competitiveness between production of energy maize and food. Impacts on agricultural income and subsidies are small while increased environmental pressure is expected in the event of a significant expansion in energy crop production. Two nitrogen reduction scenarios simulate policy measures according to the water framework directive (WFD) and the OSPAR convention. The scenario according to the WFD (limitation of organic nitrogen input to a maximum of 170kg nitrogen per hectare) does not result in any impacts. In contrast, the scenario according to the OSPAR convention (reduction of nitrogen input quantities by 10%) results in a decrease in environmental pollution and is accompanied by a reduction of income and reduction of agricultural production under land abandonment. In the scenario of mandatory agri-environmental measures (AEM) it is assumed that the area with applied AEM is extended. The increase of AEM area results in a decrease in cereal production and a reduction of environmental pollution, while income decreases only slightly. Two combined scenarios simulate a mix of different policy and market situations which provoke an intensive and an extensive agricultural production. The results of these scenarios illustrate the interaction of the single policy measures. The measures of subsidy reduction have similar reducing impacts on income and subsidy volume in both scenarios. In the intensive production scenario high competitive energy crop production and a less restrictive nitrogen restriction result in a compensation effect of land abandonment by extension of energy crop area. In the extensive production scenarios, less competitive energy crop production and a high restrictive nitrogen constraint result in reduced agricultural production, increased land abandonment and reduced environmental pressure. In order to evaluate the impact of the simulated policy measures on the achievement of policy objectives the results of all scenarios are compared and ranked according to their impact on the policy objectives. The analyses of the model results show impacts of policy measures which are likely to be expected. However, the analyses at NUTS3 as well as farm types' level reveal that the impacts of the policy measures can be regionally quite different. Thus the detailed regional model results clearly show that (and where) the implementation of agricultural policy measures requires a regional specific evaluation and monitoring. In order to discuss the study with regard to the methods applied and the outcome, a final strengths and weaknesses analysis was conducted. The analysis highlights the strengths of the study (e.g. the model validation, the regional analysis of different policy scenarios, the possibility of cooperation with regional stakeholders). The validation and the results of the study also show that ACRE is a suitable tool for regional agricultural policy analysis and policy decision support. Supplementary work could help to overcome single shortcomings and caveats and to further develop the model. However, ACRE can already be used now as a useful tool for the regional agricultural policy analysis of the CAP in Baden-Wuerttemberg.
An economic analysis of the implementation options of soil conservation policies
(2008) Schuler, Johannes; Dabbert, Stephan
The objective of this study is to analyze the economic and agricultural aspects of the implementation of soil conservation programmes and to suggest appropriate measure-instrument combinations for efficient soil conservation as a decision support for the implementation of soil conservation policies. Emphasis is given to the resource and institutional economics of soil conservation. In the empirical part, the efficiency of policy options is analysed using the example of a region in north-eastern Germany based on model calculations. After an introduction to the topic of soil functions and soil degradation definitions, the implementation concepts for soil protection measures at the international and national level are described. Based on the theoretical economic analysis of soils as a natural resource, the existing property rights, the public good characteristics of soils and the resulting externalities lead to the conclusion that market failure does exist. Therefore, the non-market coordination of soil use is justified. A cost-effectiveness analysis was derived based on the theory of ?safe-minimum-standard? for the appropriate assessment of the implementation options of soil conservation policies. A fuzzy-logic-based method, which is based on an expanded Universal Soil Loss Equation approach (USLE), was applied for the assessment of soil erosion risk in the sample region. The approach considers both the natural conditions and the characteristics of the cropping practice. The very detailed description of the cropping practices allowed for the specific assessment of erosion relevant effects. This, in combination with the high detail site descriptions provided this study with a very precise regional approach. The regional decision-support system MODAM (multi-objective decision support tool for agro-ecosystem management) was applied for the assessment of the economic and environmental impacts of different policy options. The policy scenarios examined include a CAP reform scenario with decoupled payments in accordance with the proposed conditions of the year 2013. This scenario was used as the reference scenario for the other possible scenarios of soil conservation policies. The three main scenarios for the policy options are 1) a non-spatially oriented, 2) a spatially-oriented incentive programmes for reduced tillage practices and 3) a regulation scenario that prohibits the cultivation of highly erosive crops (row crops) on erodible soils. The prohibition of row crops on highly erodible soils led both to lower on-farm costs and lower budget costs in comparison to the incentive programmes for reduced tillage. All three scenarios had comparable reduction in soil erosion. Based on the modeling results the ban on row crops on highly erodible sites is therefore the preferable option in terms of the cost-effectiveness ratio. The inclusion of transaction costs in this study helps expand the scope of policy analysis, for the total costs of a policy would be underestimated if only the budget costs for the direct payments to farmers were considered. Transaction costs understood as a cost for the (re-) definition and implementation of property rights can reach substantial amounts and reduce the total efficiency of a policy. The results of the qualitative analysis of the transaction costs of the study policy options also supported the option of row crop regulation on highly erodible soils. A model that serves as decision support for both the economic and agricultural aspects of soil conservation had been successfully developed in this study. Different policy options were analysed for a cost-effective solution of soil conservation programmes. Based on the final discussion on the involved transaction costs, the regulatory approach (a spatially-focussed ban on row crops) was shown to be the most cost-effective option with potentially lower transaction costs. The main criteria for a cost-effective policy design are high efficiency in both the agricultural measures (practices) and the spatial correlation between the programme area and the high erosion risk areas. Incentive programmes in combination with less effective agricultural practices showed a worse cost-benefit ratio for the sample area than the regulation approach, which is based on more effective agricultural practices.
Analysis of the effects of abolishment of planting rights in the European Union on the wine sector in Rheinland-Pfalz, Germany
(2016) Bogonos, Mariia; Dabbert, Stephan
The production and marketing of wine in the European Union (EU) are governed by the Common Market Organization (CMO) of the EU Common Agricultural Policy (CAP). Since 1976, a crucial point of the CMO with respect to wine has been the regulation of wine production by the system of the planting rights. Consistent with the goal of increasing the competitiveness of EU wine producers on the world market, the 2008 CAP reform included the liberalization of the planting rights regime by 2018 the latest. As a result of intense discussions on the EU and EU Member states levels, the planting rights system has recently been converted into a scheme of authorizations for vine plantings, which is valid until 2030. This dissertation investigates the effects of abolishment of planting rights on the largest wine-producing region in Germany, Rheinland-Pfalz. For this purpose a comparative static regional partial net-trade equilibrium model that includes the output of a Markov chain projection was used. The model simulates the future distribution of vineyards in Rheinland-Pfalz among wine farm groups according to size classes and area type, the demand for standard and basic quality wine must in Germany and production of standard and basic quality wine must in Rheinland-Pfalz. The policy simulation model was run for scenarios of different levels of market prices of wine must, different land rental prices, restricted and liberalized planting rights, and a scheme of authorizations for vine plantings. The results revealed that the effects of liberalization of planting rights and of a scheme of authorizations for vine plantings depend on profitability of standard and basic quality wine must production. In particular, if standard and basic quality wine must production is profitable for at least one wine farm group, and planting rights are liberalized, production of standard and basic quality wine must and, respectively, acreage of vineyards in Rheinland-Pfalz will increase with respect to the demand for these two types of wine must in Germany and availability of land suitable for vine growing. If production of basic and standard quality wine must is profitable and planting rights regime is retained or converted into a scheme of authorizations for vine plantings, the acreage of vineyards in Rheinland-Pfalz might reach the maximum defined by the policy regime. In addition, newly established vineyards will be used for production of either standard or basic quality wine must depending on which type is more profitable. Movement of vineyards within the wine farm groups will take place only if at least one of the farm groups receives positive economic profits. Land for vine growing will be distributed to the farm groups which are profitable and characterized by positive growth rates in the past. The abolishment of planting rights will have minor or no effects on the wine sector in Rheinland-Pfalz, if production of basic and standard quality wine must is not profitable. Similarly, movement of vineyards within the wine farm groups will not take place, if none of the farm groups receive positive economic profits. This dissertation provided an empirical examination of the effects of restricted and liberalized planting rights, as well as a scheme of authorizations for vine plantings on the wine sector in Rheinland-Pfalz. It has also supplemented the literature on how policy reforms with regard to the limitation of agricultural production input use in order to control the output affect the agricultural production sector.
Domestic and agricultural water use by rural households in the Oueme River Basin (Benin): an economic analysis using recent econometric approaches
(2009) Arouna, Aminou; Dabbert, Stephan
Improving the management of water resources as well as an efficient use of available water are particularly important to address the increasing scarcity of water and the low level of water accessibility in many developing countries. However, better water management requires an understanding of the existing pattern of water use for domestic and agricultural activities. With a view towards contributing to such knowledge, this dissertation analyzes domestic and agricultural water use by rural households in the Oueme river basin of Benin. This is done within the scope of three research articles. The specific objectives of the dissertation were: 1) to analyze determinants of domestic water use in the rainy and dry seasons; 2) to estimate households? willingness to pay for water supply improvements and analyze its determinants; and 3) to quantify the efficiency of water use for agricultural production and identify factors explaining the differences in water use efficiency among households. The analyses are built on primary data collected from a household survey administrated to a sample of 325 households in the Oueme river basin, in 2007. To analyze domestic water demand, we identified three types of households: those that use only free water sources, those that use only purchased sources and those that combine both free and purchased sources. A system of two demand equations (one equation for free water and another for purchased water) was estimated using a Seemingly Unrelated Tobit (SURT) approach. The advantage of using the SURT approach is that it is appropriate to account simultaneously for the censored nature of water demand and the correlation between the error terms of two equations. In the analysis of households? willingness to pay (WTP) for water supply improvements, particular attention was given to the distribution of WTP, which has been addressed using (arbitrary) parametric assumptions in many previous studies. To avoid distributional assumptions, the dissertation introduced a semi-nonparametric bivariate probit approach to estimate WTP. To analyze water use efficiency, the dissertation combined an input-specific Data Envelopment Analysis (DEA) with a bootstrapped Tobit model. Bootstrapped Tobit takes care of the dependency problem between efficiency estimates. The analysis of water use efficiency focused on vegetable production in the dry season when water is scarce. Results showed that the average daily domestic water consumption per household during the rainy season (252 liters) is significantly higher than in the dry season (216 liters). SURT estimation results showed that water demand from purchased sources is perfectly price inelastic in the rainy season; indicating that rural households in Benin are very insensitive to changes in water price. This suggests that households are willing to pay more for water supply improvements, due not only to the necessity nature of water but also to its scarcity. Factors affecting domestic water use in the rainy season are household size and composition, education, time for fetching and accessibility to water sources. In the dry season, econometric analysis revealed that there is a positive relationship between wealth and the use of water from free and purchased sources. This result suggests that poverty reduces water use. Purchased water demand in the dry season is also perfectly price inelastic. However, a comparison of determinants of water use between seasons revealed that variables such as time for fetching water, access to water sources and wealth have differential influence on water use during the rainy and dry seasons. These results imply that policy makers must consider among other factors seasonal variation of the determinants of water use. The results of this dissertation provided the first evidence that, in rural Benin, households wanting to improve water supplies are willing to pay more than existing water prices. Households are willing to pay over one and a half times the present average water price. Furthermore, results revealed that estimated WTP would generate substantial revenue from the community, which can lead to significant reductions in subsidies. The supply of safe and adequate water based on estimated WTP will reinforce both the participation of the rural population in water supply management and the sustainability of water facilities. A related policy is that a demand-side management approach can be successfully implemented in rural areas for water supply improvements and sustainability. The important determinants of WTP for water supply improvements were education, age of household head, wealth, queue time at existing water sources and preferred improvements. The policy implication of these findings is that a combination of socio-economic factors affecting WTP, and a demand-side management approach, are likely to improve the sustainability of water projects in rural areas of Benin. Average water use efficiencies were 0.38 and 0.50 under constant and variable returns to scale specification, respectively. This implies that if vegetable farmers in the study area become more efficient in water use, significant amounts of water could be saved and made available for dry season farming land expansion. In addition, many farmers operated at an increasing return to scale (average scale efficiency is 0.70), revealing that most farms should be larger than they currently are to produce efficiently. Water use efficiency in vegetable production was determined by market access, land fragmentation, extension service, ratio of children to adults, water expenditure, water sources, off-farm income and wealth. Results suggest that policy makers should focus on improving farmers? access to input and output markets as well as their access to technical information and training through extension service or NGOs. The findings also showed that households paying for irrigation water or systems are more efficient in water use. However, any price policy should be combined with other policy options such as training and development of improved irrigation techniques adapted to socio-economic conditions of farmers. Overall, various socio-economic characteristic of households and institutional factors are found to explain water use for both domestic and agricultural activities. These factors must be carefully considered for the design and implementation of water management programs that can lead to sustainable accessibility to water. Although the research focuses on Benin, most of the conclusions and policy implications are relevant and could be applicable to many developing countries with similar socio-economics conditions. The dissertation also applies and extends recent econometric approaches that may be used for empirical studies on water management policy in developing countries.
Economic analysis and policy implications of wastewater use in agriculture in the central region of Ethiopia
(2008) Weldesilassie, Alebel Bayrau; Dabbert, Stephan
The general objective of this study was to analyze the impact of wastewater use in agriculture. It mainly focused on three aspects of wastewater use for irrigation and their policy implications: impact on crop production and productivity; its impact on the health of farmers; and the value attached to its safe use for irrigation. The main objectives of the study were, therefore, 1) to define the farming system of wastewater farmers and to analyze the impact of wastewater on crop productivity; 2) to analyze the prevalence of the actual health risks to farmers and estimate the health costs associated with the use of wastewater in irrigation; and 3) to estimate the farmer?s willingness to pay for improved or safe use of wastewater for crop production. This study used mainly primary data collected from a household survey conducted on 415 wastewater and freshwater farm households operating irrigated agricultural activities within and around Addis Ababa, a central region of Ethiopia. A Cobb Douglas production function is specified to analyze the impact of wastewater on crop productivity. The production function was estimated using a Censored Least Absolute Deviation (CLAD) econometric model. To analyze the health impact of wastewater, the probability of illness was estimated based on the theory of the utility maximizing behavior of households subject to the conventional farm household production model modified by adding a health production function. The economic value of safe use of wastewater is estimated from data obtained from a contingent valuation survey administered by in-person interviews. A dichotomous choice model is used to elicit the farmers? willingness to pay. Bivariate probit and interval regression models are used to analyze the factors determining the farmers? willingness to pay for safe use of wastewater for crop production. The study shows that the livelihoods of wastewater farm households depend on the wastewater farm. Income from a wastewater farm accounts for 62% of total annual household income, ranging from 27% to 97%. About 61% of the vegetable market of Addis Ababa, the capital city of Ethiopia with more than five million people, is produced from the wastewater farms. Leafy vegetables, which are eaten raw, are mainly produced in less polluted wastewater farms and root vegetables are produced in more polluted wastewater farms. The study revealed that wastewater farm households use significantly less doses of chemical fertilizer compared to the freshwater irrigators. However, they spend three times more on seed and five times more on farm labor. Net farm return per hectare of plots irrigated with wastewater is significantly higher than for plots irrigated with freshwater. The results also indicate that the predicted median output value per hectare is significantly higher in wastewater irrigated plots compared to plots irrigated with freshwater. The CLAD estimation result shows that higher productivity of wastewater plots is explained by investments in inputs (organic fertilizer, improved seed and agricultural extension services), ownership of plots and levels of pollution of the irrigation water. The overall effect of wastewater on crop productivity is negative and insignificant (compared to freshwater). Plots irrigated with less polluted wastewater are more productive than plots irrigated with more polluted wastewater. The implication of the result is that even if wastewater is a reliable source of irrigation water and contains essential plant nutrients such as NPK, the nutrient content exceeds the recommended level of the plant requirement (e.g. nitrogen) or it contains toxic elements (e.g. nickel, zinc) above the recommended limit, and thereby reduce yield. Due to unsafe wastewater irrigation systems, wastewater use in irrigation actually poses health risks to farmers. Apart from working on wastewater farms, different risk factors prevail that can cause wastewater-related diseases in the studied areas. This study shows that major risk factors causing illness are household demographic characteristics, hygienic behavior of farm families and poor access to sanitation services. Lack of awareness on health risk of wastewater as well as working without protective clothing on the farm are also important risk factors in the study area. The distribution of these risk factors varies between the wastewater and freshwater irrigation areas. The most common incidence of illness reported by farm households are intestinal infection due to hookworm and Ascaris, diarrhea and skin diseases, which also varies between the two groups of farmers as well as within the different areas of wastewater. The findings of this study show that the prevalence of illness is not only significantly higher in farmers working on wastewater farms compared to freshwater irrigators, but is also significantly higher in wastewater areas where the pollution level is higher. The probability of being sick with an intestinal illness is 15% higher for wastewater farmers than for freshwater farmers. Use of protective clothing during farm work and awareness of health risks in working on wastewater farms significantly reduce illness prevalence. In addition, hygienic behavior of farm families including eating safe raw vegetables, compound sweeping, and washing hands before a meal are important determinants of illness prevalence in wastewater irrigation areas. Therefore, use and provision of protective clothing at affordable prices, creating awareness for safe use of wastewater, and reducing the pollution level of irrigation water can significantly decrease the health risk of wastewater use in irrigation. While each of these policy interventions has a significant effect in reducing health risks, combining these measures will result in more significant reduction of health risks to farmers, and thereby maximize the benefit from the wastewater resource as a source of livelihood and vegetable supply to the residents of nearby cities. Farmers are willing to contribute money to improve the existing unsafe irrigation system. Two options were suggested by farmers to improve the existing situation: enforcing laws against polluters who discharge their wastewater without any kind of treatment, and awareness creation of safe use of wastewater for irrigation. Farmers are willing to pay for the improvement programs and there is a welfare gain to the society from safe use of wastewater for crop production. The benefit from irrigated-farming, membership to water users? association, yield value, off-farm income and working on a wastewater farm all significantly determine the farmers? probability of accepting offered bids for the improvement program. In addition to these variables, multi-purpose uses of irrigation water as well as education level determines the farmers? willingness to pay. Irrigation method has no significant effect on the farmers? willingness to pay, implying that introducing water saving and improved irrigation techniques has an important role in improving the situation without affecting the farmers? willingness to pay. Overall, this study shows that wastewater is a means of livelihood for many poor households, but the existing use of wastewater for crop production actually causes health risks both to farmers and consumers. Farmers are willing to contribute to programs designed to improve the existing situation so that it is possible to maximize the livelihood benefit at minimum health risks. However, the results do not necessarily imply that the cost of improving the situation has to be borne by the farmers only. Although the study focuses on the central region of Ethiopia, most conclusions can have a wider application in other parts of the country and in many sub-Saharan African countries where wastewater is used for irrigation.
Economic analysis of organic certification systems : determinants of non-compliance and optimum control strategies
(2012) Zorn, Alexander; Dabbert, Stephan
Organic certification systems are prerequisite for the existence of a large-scale organic food market. Despite a well-established and generally effective control system, fraud regarding organic food that passed organic controls is detected regularly. This cumulative thesis consisting of four articles addresses current questions regarding the improvement of organic certification systems. The need for governmental supervision of an organic certification system run by private control bodies is demonstrated by a game theoretic model. A framework prepares the statistical analysis by conceptually linking factors that can influence organic control results. The case study on German supervision data from the years 2006 to 2008 reveals significant differences between private control bodies regarding the number of severe sanctions imposed, i.e. fundamental control results. These data that were collected for supervision of the control system, however, are not sufficient to explain these differences. This is due to shortcomings in the data collected. Key terms of the data are not defined and the variable definitions seem to change over time. This study concludes that there is more detailed and reliable data from organic control bodies needed to understand the determinants of non-compliance with an organic standard. Detailed data on organic farm controls from the years 2007 to 2009 were supplied by two control bodies. Theoretical considerations founded on the ?Economics of Crime? approach yield hypotheses on factors affecting non-compliance with an organic standard. The data provided by a German and a Swiss control body are analysed by two different logistic regression models. The probability of receiving a sanction (which is used as proxy for non-compliance) is estimated on farm level by using data on farm and farm production. Such an approach to assess the determinants of non-compliance has not been used previously in the literature. Given the gradual sanction system, an ordinal logistic regression model is appropriate for the analysis of the German data. Swiss data are analysed by a random effects logistic regression model. Both models confirm some of the factors contributing to the risk of non-compliance that are applied in qualitative risk assessment so far. Control results from previous years, the overall farm complexity and the farm livestock production complexity, as well as farm size are factors that increase the probability of receiving a sanction. Risks connected to specific crops or livestock types that could come along, e.g., with particular requirements of the production method cannot be confirmed across the models. The explanatory value of both models is likely to be improved by the integration of further variables, such as data on farmers? personal and financial characteristics. The heuristic model builds on the results of the econometric models. This model adopts a societal view on the control system by considering the costs of controls and the damages resulting from non-compliance with an organic standard. Monte-Carlo simulations illustrate the relationship between important parameters for optimising control strategies. These simulations show that even without fines a situation can occur where most operators comply. The different approaches to analyse control data encounter difficulties inherent to the control data. In this context, the dark figure consisting of undetected non-compliances, inhomogeneous detection probabilities linked to particular production methods, and a potential positive confirmation bias connected to the risk based control approach are especially relevant. The working hypothesis that these potential biases are distributed randomly deserves closer attention in subsequent studies. Such future analysis should be based on even more detailed data, e.g., pooling original data from different control bodies in a control system. Such a data base would allow focusing on severe non-compliances which occur only rarely. Furthermore, pooled data could be used to investigate issues that are fundamental for the supervision of a control system such as a control body effect on the detection of non-compliance. This thesis presents important results that can be consulted for further analysis of organic control systems. Beyond, the approach, the methods used, and the results obtained are of general relevance for food certification systems beyond the organic sector.
Jahresbericht 2012 / Universität Hohenheim
(2013) Universität Hohenheim; Dabbert, Stephan
Jahresbericht 2016 / Universität Hohenheim
(2017) Universität Hohenheim; Dabbert, Stephan
Jahresbericht 2017 / Universität Hohenheim
(2018) Universität Hohenheim; Dabbert, Stephan
Jahresbericht 2018 / Universität Hohenheim
(2019) Universität Hohenheim; Dabbert, Stephan
Jahresbericht 2019 / Universität Hohenheim
(2020) Universität Hohenheim; Dabbert, Stephan
Jahresbericht 2020 / Universität Hohenheim
(2021) Universität Hohenheim; Dabbert, Stephan
Jahresbericht 2021 / Universität Hohenheim
(2022) Universität Hohenheim; Dabbert, Stephan
Jahresbericht 2022 / Universität Hohenheim
(2023) Universität Hohenheim; Dabbert, Stephan
Jahresbericht mit Zahlenspiegel 2013 / Universität Hohenheim
(2014) Universität Hohenheim; Dabbert, Stephan
Jahresbericht mit Zahlenspiegel 2014 / Universität Hohenheim
(2015) Universität Hohenheim; Dabbert, Stephan
Jahresbericht mit Zahlenspiegel 2015 / Universität Hohenheim
(2016) Universität Hohenheim; Dabbert, Stephan
Land use management under climate change : a microeconomic analysis with emphasis on risk
(2018) Reinmuth, Evelyn; Dabbert, Stephan
This cumulative dissertation was conducted under a grant from the German Research Foundation (DFG) for the research group FOR 1695 - “Agricultural Landscapes under Global Climate Change – Processes and Feedbacks on a Regional Scale”. The goal of the sub-project from which this dissertation stems from was to explore, extend and strengthen the scientific basis for learning and risk strategies and the adaptation behavior of farmers’ economic planning decisions in crop production under the influence of climate change. The integrated bioeconomic simulation model FarmActor, was to be used as an experimental tool to develop an interdisciplinary methodological approach supported by empirical work in two study regions in Southwest Germany, the Kraichgau and the Swabian Alb. This dissertation examines risk in the context of land use management and specifically crop production. Risk in this context is related to how outcome distributions are affected by climatic influences. Risk strategies assess these contributions and account for them in the resulting decisions. The thesis is written as a cumulative dissertation and is composed of five articles. Four articles have been published by peer-reviewed journals. A fifth article has been published as a peer-reviewed conference proceeding. The article at fifth place represents the results of the main focus of this dissertation as presented in the following. Available economic models assume that farmers assess climatic risks only through yields or costs when building their land use management risk strategy for crop production. However, the available methodological approaches have been criticized for either under- or overestimating farmers’ actual behavior. In reality, and as a basis for field allocation planning, farmers have additional knowledge from monitoring crop development throughout the whole season. Yield is actually just the last point in a long sequence of (economic) evaluative observations about the production process. This influences how farmers define not only the riskiness of a yield distribution but also its costs. We hypothesize that, because it is not possible to methodologically integrate process evaluations in economic planning decisions, models lack performance, and as a consequence, it is very difficult to conduct proper research on the climate’s influences on land use management decisions. In this original research, we present a newly developed downside risk measure based on evaluations throughout the production process that can be included in the planning process as an additional parameter—so-called Annual Risk Scores. A comparative static analysis was performed to demonstrate how ARS scores assess future climatic conditions in the example of winter wheat production in the Kraichgau region as supported by empirical data. It was shown that the mechanism is sensitive to different climatic conditions. Furthermore, the ARS scores provide a different picture of climatic influence compared to an analysis based only on yields. The last article presented in this dissertation represents an integrative review that promotes more efficient model development and the reuse of newly developed methodologies in the field of integrated bio-economic simulation models. The review is based on lessons learned from working with the simulation model. Thus, the intended and outstanding full implementation of the ARS mechanism is presented in the last part of the synthesis, where we advise including the ARS scores as another constraint in the field allocation mechanisms of the FarmActor model. This is expected to improve the integration of both bio-physical and economic dimensions for complex integrated bio-economic simulation models.
Ein Nichtlineares Prozessanalytisches Agrarsektormodell für das Einzugsgebiet der Oberen Donau
(2005) Winter, Thomas; Dabbert, Stephan
This dissertation describes a regionalised non-linear agricultural sector model for the upper danube catchment area. The model is used for simulating and forecasting the impacts of different policies measures and of climate change on farming. The most important task of this model is to fit as a part into the decision-support-system Glowa-Danubia. The main idea of the decision-support-system is, that the impact of the Global-climate change to the water on the upper danubia basin can be shown. At first the interactions between agriculture and water are defined. One of the results is that agriculture is an economic sector, which has an important influence on the water-household of the landscape. Many agricultural activities, e.g. tillage, fertilisation, plant-protection have a direct or indirect impact on the waterhousehold. Of course there are some conflicts with other users of the water resource. In consequence a lot of laws guarantee the safety of the water resources. The farmers are bound by law to practice the so called ?good agricultural practice?. Another possibility for policy to influence farmers is that farmers can take part in agri-environmental programs. In the second chapter the connections between the agricultural sector model and the other models are defined. A division of the agricultural sector model into three main modules is necessary, that the dates can be transferred automatically. The three modules of the agriculture sector model can be overwritten with data resources, model equations and result tables. A process-analytical optimisation model was used, because with this methodological approach the use of fertiliser and other farm inputs and the level of production can be simulated. In the plant production 19 different crop production activities with two different intensities were defined. The production level of each crop was defined by using expert interviews with a Probit-Model. The Probit-Model calculates independ of the ?Landwirtschaftliche Vergleichszahl? (a relative number, which indicates the agronomy quality of soils) in order to define the extent of both intensities. In the animal production 15 different production systems are defined. The constraints and the calibration of the non-linear gross margin function are discussed after the definition of the production activities. Some constraints, for example the crop rotation constraint, are not necessary in the non-linear model. The reference situation is the year 1995. The first simulation shows the results for the year 1999. In the Ex-post-analysis from this year both different Howitt-methods, the cost side specification and the yield side specification of the non-linear gross margin function, get compared. Both methods calculate nearly the same results, the forecast of the production activity levels and the gross margins are nearly the same. For the total research area both methods either over- or underestimate the production activity levels for the same crop. If the forecast results are compared by district the forecasting accuracies were different. A system, that one method is better than the other method, can not be found. For the simulation of the scenarios the cost side specification was used. In the first scenario the year 2008 under the conditions of the agenda 2000 was calculated. The production levels are nearly the same as in the reverence year. The consequences of the mid term review of the European Commission are forecasted in the two other scenarios. The conditions under mid term review have a big impact on agriculture, because of the decoupling of the agricultural subsidies from the products. In both scenarios, the cattle meat production decreases. The same results can be shown with the reduction of silo maize and of grassland. On the other side set aside arises in all districts. Positive for the water resources are the reduction of nitrogen load from organic manure. One of the main conclusions is that the positive quadratic programming is an alternative to the linear models for analysis of farms by district level. Of course the aggregation mistake from the aggregation of different farm types to one big district farm can not be carried out. But the positive aspects of the PQP, which are described in literature, can be permitted. A further research theme, which is not answered in this thesis is the combination of the non-linear gross margin with useful econometric methods.
Participatory evaluation of sustainability of farming systems in the Philippines
(2010) Vilei, Sonja; Dabbert, Stephan
Forest cover in the Philippines has been greatly reduced in the past and slightly recovered since, estimated at around 24% of land surface currently. Small-scale farmers have to survive on small landholdings (2 ha on average and mostly under 5 ha), face insecure land tenure, and the high population density leaves little scope for gaining new agricultural land. Their farming systems continue to form an important part of their livelihoods, but often their strategies are unsustainable in the long run. While the need for evaluating common farming systems and compare them with new alternatives exists, it is important to involve local stakeholders in the search for suitable sustainability indicators. In this study, the search was based on the Sustainable Rural Livelihoods Framework and therefore organised under its five types of capital assets: natural, financial, physical, human and social capital. Farmers from five study sites along the Western side of the island of Leyte were gathered in eight focus group discussions to discuss the issues of success and sustainability of their farming systems and identify and rank possible criteria for an evaluation of sustainability. Nine other stakeholders from the same sites were interviewed individually. In a second research phase, all 49 identified criteria were given to 30 farmers and 18 other stakeholders for ranking. Three groups of farmers from the municipality of Baybay were used for comparison: one group of rice and coconut farmers; a second group with (additional) exotic timber trees (usually Gmelina and Acacia mangium); a third group with (additional) indigenous timber trees (?Rainforestation Farming?). The identified indicators were tested regarding their usefulness for comparing the three groups of farmers. Rainforestation Farming, as promising alternative farming system, was analysed further regarding financial aspects and its adoptability with regard to small-scale farmers. The Sustainable Rural Livelihoods Framework was useful for identifying suitable evaluation criteria. The importance of the five capital assets groups was perceived similarly by farmers and other stakeholders, but ranking results for single criteria (i.e. soil quality, membership in organisation) differed. The same holds true when comparing results for the four study regions, where the individual ranking was carried out: significant differences existed for single, mostly financial, criteria (i.e. record-keeping, investment costs) but not for importance of the five capital asset groups. The ranking results differed quite substantially, though, between focus groups and individual farmers, indicating on the one hand the influence of group leaders. But, on the other hand, farmers had the complete list of criteria for the individual ranking, including several criteria which they had not thought of previously, but which they still regard as important. Fifteen criteria were selected as indicators for comparing the three farmers groups. Rainforestation farmers were the group scoring significantly higher on most indicators (i.e education level adults and children, land available per capita, (perceived) soil quality, number of soil conservation measures used, membership in organisation) than farmers without timber trees. Farmers having planted exotic timber trees scored closer to Rainforestation farmers. But to be able to judge if the specific farming system leads to a more sustainable livelihood, time series data would have been necessary. The data of this study allowed concluding that tree farmers planting (indigenous or exotic) timber trees are endowed with higher resources ? more land, higher income, higher education levels. Most likely they had these resources before starting their farming systems. In addition, these farmers were also more actively engaged in organisations and had more contact to extension agents, therefore enhancing their social (and human) capital. The higher score regarding (perceived) soil quality and (non-) use of pesticides these farmers groups reached are likely to be an outcome of the farming system practiced. Analysing the financial feasibility and adoptability of Rainforestation Farming, it shows that the system has the potential to be profitable, but coming with a high risk: investment costs are very high and it takes up to 13 years to regain them. Consequently, the first adopters either had unused land areas or substantial off-farm income, and the subsequent adoption rate is low. Sustainability has to be understood as a dynamic and not a static concept and the concept of sustainable land management must consequently evolve as well. This study tried to add further findings regarding the use of suitable methods for this cause, but as already mentioned above, time series data would be necessary to assess the progress of farming systems towards ?sustainability?.