A mathematical programming approach to model the impacts of sectoral interventions on sustainable development in rural sub-Saharan Africa

authored by

Steven Gronau

supervised by

Ulrike Grote

Abstract

Malnutrition, poverty and the unsustainable exploitation of natural resources pose serious problems in sub-Saharan Africa (SSA). Overfishing and deforestation not only damage ecosystems, but also put livelihoods at risk in rural economies. The development of nature-based tourism, aquaculture and bioenergy production from papyrus briquettes provide opportunities for improvement. Co-management is becoming increasingly important in SSA to prepare and implement development plans. It aims to provide a framework in which governments work closely together with key stakeholders in village communities, but often success has been limited. Namibia and Zambia are used as case studies in this thesis because despite co-management, malnutrition, poverty and high exploitation of natural resources is evident. A modeling approach can evaluate the impact of different policy (or development) programs ex-ante in order to derive recommendations for action. Quantitative approaches such as computer-based mathematical programming therefore provide an important tool to support policy planning and explore development opportunities, as simulations can indicate the feasibility and potential acceptance of policy (or development) programs. As a result, there is great interest in computer-based models to support the design of development and management plans. The literature also points to research needs for nature-based tourism, aquaculture and papyrus briquettes as bioenergy in SSA. This need is addressed in this thesis by developing computer-based mathematical programming models. Against this background, the overall objective of this thesis is to develop computer-based mathematical programming models to investigate the impact of different development opportunities on rural economies and natural resources in SSA. The focus of this thesis is on nature-based tourism and aquaculture applied to a region in Namibia, and papyrus briquetting applied to a rural area in Zambia as possible (management) options. In detail, the following research questions are raised: (1) Does nature-based tourism improve local livelihoods? (2) Does nature-based tourism have the potential to reduce overfishing? (3) Does aquaculture improve local livelihoods? (4) Does aquaculture have the potential to reduce local overfishing? (5) Does papyrus harvesting and processing improve local livelihoods? (6) Does papyrus harvesting and processing have the potential to reduce the pressure on local forest resources? Chapter 2 investigates the impact of nature-based tourism on rural development and conservation in Namibia’s Zambezi Region. Co-management and nature-based tourism often go hand in hand to drive conservation and economic development in SSA. However, the complementarity of the two strategies is controversially discussed in the literature. A mathematical optimization model was developed which represents the economy of a rural case study region and analyzes the trade-offs between nature conservation and development objectives. The model is based on survey data from 200 households collected in 2012. Two different modeling scenarios were developed. Results show that in the scenario describing unrestricted resource extraction, local communities mainly benefit from fishing and utilizing forest products. The current problem of overfishing is highlighted and would be further worsened by the absence of the angling tourism sector. Furthermore, important macro- and micronutrients are missing in the daily diets. In comparison, the scenario representing the social optimum, implying sustainably managed fish stocks and appropriate diets for community inhabitants, shows that community households increase agricultural diversification and shift livelihoods towards tourism employment. As long as appropriate dietary substitutes for fish are available, the overall welfare can be maintained. Model results indicate the high willingness to pay for fish of angling tourists compared to local consumers. Revealed marginal values provide information for developing sustainable regional management plans and guide values for development interventions. Nature-based tourism thus has the potential to improve livelihoods and stop overfishing. Chapter 3 examines the impact of aquaculture development on fish stocks and livelihoods in rural Namibia. Aquaculture is widely recognized as a way to reduce malnutrition and poverty. So far, research with respect to aquaculture has mainly focused on Asia, and the few studies available from SSA are predominantly ex-post partial analyses. A village Computable General Equilibrium (CGE) model was constructed to investigate whether aquaculture improves local livelihoods and simultaneously has the potential to counteract local overfishing. The model is applied to a rural case study region in Namibia’s Zambezi Region where malnutrition, poverty and fish resource overexploitation pose current problems. A Social Accounting Matrix (SAM) from 2012 is used as a database for the analysis. The village CGE model shows that aquaculture is a viable livelihood activity improving household incomes and utility through labor reallocations. Furthermore, aquaculture can counteract malnutrition through increased fish consumption. Higher opportunity costs lead to households leaving the fisheries and switching to aquaculture. These substitution effects offer the possibility of reducing the pressure on local freshwater fish stocks. The results also predict that the price of fish from aquaculture is below the regional market price and thus more affordable for the poor. However, the subsistence fish harvest still exceeds the sustainability limit, and the simulation of a strict fish conservation policy leads to declining incomes and increasing deforestation. Policy makers can use the results to introduce aquaculture support programs in rural areas. The findings indicate that such interventions should take particular account of the poorest households, which are most dependent on fisheries. The derived opportunity costs provide information about payments that are necessary to make policy interventions acceptable for different household groups. Chapter 4 analyzes the impacts of introducing a small-scale papyrus briquetting business in rural Zambia. Papyrus is increasingly suggested as an alternative bioenergy source to reduce the pressure on forest ecosystems. However, there are few studies on the economic viability of papyrus wetlands and the benefits for local communities. A village CGE model was developed to examine whether papyrus harvesting and processing has the potential to improve local livelihoods and simultaneously counteract the pressure on local forest resources. The model is applied to a village in northern Zambia where overexploitation of forest resources to produce energy from firewood and charcoal poses a serious problem. The analysis is based on a SAM, which was constructed from survey data of 105 households collected in 2015. The model results show that papyrus briquettes are a possible alternative biofuel and that this technology of papyrus briquetting improves household income and utility through labor reallocations. Higher opportunity costs lead to households switching from firewood extraction and charcoal production activities to papyrus harvesting and processing for bioenergy production. Revealed group-specific opportunity costs of the CGE analysis represent the incentive price for households to stop deforestation. Replacing energy supplies from firewood and charcoal with papyrus briquettes results in substitution effects between forest land and wetland and thereby reduces the pressure on local forest resources. However, sustainable harvesting regimes are required to maintain papyrus as an alternative biofuel source. The CGE approach allows for an economy-wide ex-ante analysis at village level and can support management decisions to ensure the success of papyrus bioenergy interventions. Annex A contains a user manual for the construction of a SAM for a village economy. The methodology is well established at the national level. The procedure for developing national SAMs is extensively documented in literature. However, it can also be constructed for smaller economies, such as a village. Studies dealing with village SAMs are rare. In addition, there are hardly any guidelines for design. In order to complete this gap, theoretical principles and data requirements are discussed; a hypothetical village SAM is constructed by using numerical examples. Subsequently, the SAM of a real-world village case study from Zambia is analyzed. It is demonstrated how macroeconomic indicators can be calculated and microeconomic information obtained. Furthermore, a village SAM provides the database for scientific modeling approaches, such as optimization and CGE models, which are presented. Village SAMs are thus a useful management tool and support policy planning at local and regional level.

Organisation(s)

Institute of Environmental Economics and World Trade

Type

Doctoral thesis

No. of pages

18

Publication date

2019

Publication status

Published

Sustainable Development Goals

SDG 2 - Zero Hunger, SDG 8 - Decent Work and Economic Growth, SDG 15 - Life on Land

Electronic version(s)

https://doi.org/10.15488/4437 (Access: Open)