<p>This dissertation investigates the economic behavior of families in developing settings. Utilizing uniquely rich, longitudinal survey data from Indonesia, it demonstrates the complexity of market environments facing rural households, as well as the importance of extended family networks in determining the health and well-being of young children. These essays serve as an illustration of advances in development economics that are possible when fundamental models are revisited and examined with new longitudinal data. The results of these exercises are important not only for updating economic models of behavior, but for what they reveal about the complexities of decision making, and for the effective design and evaluation of development policy around the world.</p> / Dissertation

This study had two main objectives. The first objective was to determine the factors that influence rural households’ labour allocation and supply decisions for competing livelihood activities, including wetland activities. The second objective was to: develop an ecological-economic model establishing the linkages between the economic and ecological components in a wetland system and apply the model to evaluate the impacts of alternative wetland management and policy regimes on wetland functioning; and supply ecosystem services and economic well-being. To achieve the first objective an agricultural household framework was used. The reduced form labour use and supply equations for wetland products and agricultural grain, derived from optimising the agricultural household model, were estimated jointly using a seemingly unrelated regression model. The model was fitted to data collected from a survey of 143 households in a wetland system in the Limpopo basin of South Africa. Results showed that poor households, most of whom are female-headed households, have less capacity to participate in off-farm employment and rely heavily on farm and wetland activities for their livelihood. This implies that environmental protection policies that limit access to the wetland resources will deepen poverty as the poor will suffer more from deprivation of resources, which play a key role as a livelihoods safety net for the poor. This suggests that in order to enhance the sustainable management of wetlands there is need to identify and promote local level wetland management practices that allow the poor to use wetlands to enhance their economic well-being with minimum adverse effects on wetland ecological conditions instead of adopting strict wetland protection measures. In addition, there is also a need to broaden the opportunities for the poor to diversify into off-farm livelihood activities. This minimises the risks of income fluctuations associated with farm and natural resource-base livelihood sources and therefore provides the necessary positive incentives for wetland conservation and sustainable use. Better access to education is an important instrument for enhancing the poor’s ability to diversify into off-farm livelihood options. These results suggest that wetland conservation and sustainable use has to be integrated with the broader rural poverty reduction initiatives such as: improved access to education; investment in irrigation infrastructure; and improving access to markets. Results also indicate that a household’s exogenous income and wealth status (asset endowment) enhance farm production whilst reducing dependence on wetland products for livelihood. The government should pursue policy measures that reduce rural household liquidity constraints and enhance investment in productive assets (e.g. improving rural household access to credit and off-farm income opportunities) to boost farm production and enhance wetland conservation and sustainable use. To achieve the second objective the study developed a dynamic ecological-economic model. The model is based on the system dynamics framework to capture the multiple interactions and feedback effects between ecological and economic systems. The application of the model in simulating policy scenarios suggests that wetland ecosystem services (crop production and natural resource harvesting) are interlinked with trade-offs involved through their competition for labour, water and land resources. Policy scenario simulation results showed that diversifying livelihoods out of agriculture simultaneously improves economic well-being and enhances wetland conservation. Pure conservation strategies impose significant losses in the economic welfare of the local population unless supported by diversification of livelihood sources. The simulation results also show that the development of a competitive marketing system for harvested biomass products increases returns to wetland biomass products relative to that of wetland grain and it reduces conversion of wetlands to agriculture. Simulation of the predicted reduction in annual precipitation due to climate change in southern Africa showed that climate change is likely to accelerate the conversion of wetlands to agriculture, confirming the important role wetlands play in managing climate variability in smallholder agricultural systems. Government policies that support livelihood diversification into off-farm livelihood opportunities and improve the capacity of the rural poor to adapt to climate change, especially droughts, are critical for wetland conservation and sustainable use. / Thesis (PhD)--University of Pretoria, 2011. / Agricultural Economics, Extension and Rural Development / unrestricted

Le salariat agricole a toujours été invisible, socialement et politiquement. Pourtant, bien que son poids se soit réduit au XXe siècle, son rôle reste encore important dans l'agriculture familiale française. Sa place se renforce et sa nature se modifie : le travail saisonnier se développe. Dans un contexte d'exacerbation de la concurrence, la compréhension des déterminants de ces mutations et de leurs implications est au centre d'un double enjeu : social et de compétitivité. Selon nous, la distinction faite en économie agricole entre famille et salariat est insuffisante pour saisir ces évolutions et leurs impacts sur la performance des exploitations. Nous analysons, théoriquement puis économétriquement, les déterminants de la demande de travail des exploitations familiales en distinguant les salariés permanents des saisonniers. Nous montrons qu'une telle distinction permet de mieux comprendre le comportement des exploitants, de révéler des phénomènes de substitution entre les deux types de salariés et d'expliciter les mécanismes sous-jacents à ces phénomènes. Nous étudions, de plus, le lien entre la main-d’œuvre des exploitations et leur performance. En estimant une fonction de production, nous montrons que les trois types de travail sont inégalement productifs et que la composition de la main-d’œuvre influence la productivité des exploitations. Enfin, par l'analyse qualitative d'un contrat saisonnier particulier et de la flexibilité du travail qu'il offre, nous montrons que les formes d'emploi en agriculture sont plus complexes que la dichotomie permanents-saisonniers et qu'elles invitent à revenir sur le dualisme des formes de flexibilité du travail de la littérature. / Wage labor in agriculture has always been characterized by some invisibility, whether it is in the social or political field. Although its importance has been reduced throughout the 20th century, it still plays an important role in family farming in France. This role has developed and its very nature changes as seasonal work increases. At a time of increasing competition, understanding these evolutions, their determinants and consequences therefore becomes a double issue of study : a social one and one of competitivity. It is our opinion that the classical dichotomy between family work and wage labor is insufficient when highlighting evolutions in the workforce and its impact in terms of the performance of farms. The factors of family farming labor demand are analysed, theoretically and econometrically, by differentiating permanent workers from seasonal ones. Such a distinction gives a better understanding of the farmers' behaviour, shows the substitution phenomena between these two types of workers, and gives the reasons for such a substitution. The link between workforce composition and farm performance is also studied. By estimating a production function, we show that the three types of workers are unequally productive and that workforce composition affects farm productivity. Lastly, the qualitative study of a specific seasonal contract and that of the type of labor flexibility such a contract offers, sheds light on how jobs in agriculture are much more complex than the strict division between permanent and seasonal workers. Indeed, they call for a questioning of the dual aspect of labor flexibility generally used in the economic literature.

Dans le but de faire face aux défis interdépendants en termes d’épuisement des ressources énergétiques, de dégradation environnementale et des préoccupations de santé publique dans le contexte chinois en réponse au développement durable, nous nous concentrons sur l'étude des politiques en matière d’énergie, d’environnement et de santé en Chine. Dans le chapitre 1, nous donnons un aperçu des politiques chinoises en matière d’énergie, d’environnement et de santé au cours des 20 dernières années afin de connaître les orientations politiques futures auxquelles le gouvernement n'a pas donné une attention suffisante. Dans les trois chapitres suivants, nous proposons une série d'études empiriques afin de tirer quelques implications politiques utiles. Dans le chapitre 2, nous étudions l'impact de l'urbanisation, de l'adaptation de la structure industrielle, du prix de l'énergie et de l'exportation sur les intensités énergétiques agrégés et désagrégés des provinces. Dans le chapitre 3, nous étudions les facteurs qui expliquent la transition énergétique vers des combustibles propres des ménages ruraux. Dans le chapitre 4, nous examinons les effets conjoints des risques environnementaux, du revenu individuel, des politiques de santé sur l'état de santé des adultes chinois. En particulier, nos résultats empiriques suggèrent d’intégrer le développement urbain dans la stratégie d'économies d'énergie; de considérer des substitutions/complémentarités complexes parmi les sources d'énergie et entre l'énergie et l’alimentation pour les ménages ruraux; d’aligner les politiques environnementales, énergétiques et alimentaires avec les politiques de santé. / With the purpose of coping with the intertwined challenges of energy depletion, environmental degradation and public health concerns in the Chinese-specific context in response to sustainable development, we focus on investigating China’s energy, environment and health policies. In chapter 1, we provide an overview of China’s energy, environment and health policies over the past 20 years in order to know about the future policy directions to which the government has not given a sufficient attention. In the following three chapters, we provide a series of empirical studies so as to derive some useful policy implications. In chapter 2, we investigate the impact of urbanization, industrial structure adjustment, energy price and export on provincial aggregate and disaggregate energy intensities. In chapter 3, we study the factors explaining the switches from dirty to clean fuel sources in rural households. In chapter 4, we examine the joint effects of environmental hazards, individual income and health policies on the health status of Chinese adults. Our empirical findings particularly suggest integrating urban development into the strategy of energy saving; considering the complex substitutions/complementarities among energy sources and between energy and food for rural households; aligning the environment, energy and food policies with health policies.