La notion de besoin caractérise souvent une nécessité biologique, le strict minimum pour se nourrir et se loger. Les besoins ont pourtant souvent été définis comme relatifs et propres à une situation donnée. Les incitations culturelles et sociales tendent à fournir des motivations puissantes aux individus, les conduisant à prendre des décisions parfois à leur détriment au plus ou moins long-terme. Ces choix révèlent certains besoins allant au-delà de la seule survie. Ma thèse a pour objectif de mieux comprendre ces décisions en incluant des composants sociaux ou culturels à la théorie standard de la consommation. Elle contribue à faire le lien entre deux branches importantes de la littérature économique: l'analyse de la demande, et l'économie comportementale/sociale. Les différents chapitres répondent à des questions telles que : pourquoi les personnes souffrant de malnutrition dépensent une part significative de leur budget en biens ostentatoires (premier chapitre) ? Pourquoi des personnes différant seulement par le groupe social auquel elles appartiennent ne consomment pas les mêmes biens (deuxième chapitre) ? Les interactions sociales contribuent-elles à la persistance de goûts locaux (troisième chapitre) ? Et l'intégration commerciale contribue-t-elle à la convergence des goûts (quatrième chapitre) ? Ces sujets requièrent de considérer la signification sociale des choix de consommation, en plus de l'effet du revenu, des prix et de leur valeur fonctionnelle. En d'autres termes, ils requièrent de penser la consommation comme un langage. / The notion of need often characterizes the strict minimum amount of food and shelter to survive. Needs have however recurrently been described as essentially relative and context-driven. Indeed, cultural and social incentives tend to provide powerful motivations for individuals to engage in choices sometimes detrimental to their short- or long-term fitness. These choices reveal certain needs which are beyond mere sustenance. My thesis aims at better understanding these decisions by including cultural and social components to a standard theory of consumption. By doing so, it contributes to bridge the gap between two important branches of the literature: demand analysis and behavioral/social economics. The different chapters adress questions such as: Why do malnourished people spend a significant portion of their budget on conspicuous goods (first chapter)? Why do people of different social groups choose to consume different types of goods, given similar prices, income and demographics (second chapter)? Do social interactions contribute to the persistence of localized tastes (third chapter)? And does market integration contribute to taste convergence (fourth chapter)? These topics require to take into account the social meaning of consumption choices, aside from income, prices and functionality. In other words, they require to consider consumption as a language.

Oportunidades is a Conditional Cash Transfer (CCT) that uses a proxy means-test targeting model to select eligible households for the programme. According to the Income and Expenditure Household Survey of 2008, approximately two in every three eligible rural households participate in Oportunidades, whereas only one in every three eligible urban households receives the Oportunidades cash transfer. This research explores the factors behind this lack of take-up, the costs of participation and the implications of targeting inefficiency on the programme’s impact on income poverty. It argues that a sample selection model is a pertinent tool of analysis as it informs on the distribution of cash transfers conditional on household eligibility. This conditional distribution is also used to understand the costs of participation as a latent variable. Eligible households are less likely to invest in human capital and neither the cash transfer nor the income forgone by children and teenagers are sufficient to overcome these costs of participation. By identifying a method to quantify behavioural change of households, I associate the costs of participation to the difficulties of inducing health-related behavioural change among recipients and eligible non-recipients. At an aggregate state level, targeting inefficiency is not fully explained by only looking at the budget constraints of the programme. In fact, targeting efficiency is positively associated to aggregate behavioural change and negatively associated to aggregate costs for participation at state level. Yet, targeting efficiency does not guarantee impact on income poverty and Oportunidades’ highest impact on income poverty also associated with the inclusion of non-eligible households in the programme. This research reconsiders the importance of the context in which CCTs are implemented and informs on the conflicting aims of CCTs: providing income poverty relief via cash transfers and incentivizing behavioural change by conditioning the cash transfer in health and education investment.

L’incertitude pèse sur les ménages ruraux des pays en développement. Cette thèse vise d’une part à mieux comprendre quels sont les conséquences de cette vulnérabilité sur les comportements et d’autre part à analyser la mise en oeuvre et l’impact des stratégies de gestion de risque, qu’elles soient internes ou externes au ménage. Le premier chapitre se concentre sur l’effet de l’exposition au risque foncier sur le comportement d’épargne en Angola. Il établit que les ménages non dotés de documents de propriété ne sont pas à même de cumuler une épargne de précaution. Ce comportement d’auto-Couverture ne se manifeste que lors du cumul de plusieurs risques. Le second chapitre se focalise sur la prise de décision à l’intérieur du ménage pour le choix de stratégies de diversification. Il s’agit d’étudier l’allocation du temps de travail des femmes au Sénégal entre le travail domestique et les activités génératrices de revenus. Un modèle de type sphères séparées avec un transfert entre conjoints est validé. Le faible rôle des incitations financières et l’importance du pouvoir de négociation sont démontrés. Le dernier chapitre analyse l’impact sur la vulnérabilité des ménages d’une intervention extérieure au travers d’un programme visant à l’accès aux services énergétiques. Son impact est mesuré sur la nutrition des enfants. Les résultats démontrent un effet positif et progressif de la présence de l’infrastructure sur la nutrition de long terme. L’intensité de fonctionnement réduit la malnutrition de court terme. Un effet de diffusion est également établi. Ces trois chapitres permettent de montrer l’incapacité des ménages à mettre en place des stratégies de lutte contre la vulnérabilité de façon autonome. Elles prouvent ensuite la nécessité de développer l’accès aux marchés dans les zones rurales. Enfin, le rôle de l’intervention extérieure pour fournir des instruments de gestion aux ménages est souligné. / Uncertainty hangs over rural households in developing countries. This thesis aims first to better understand the consequences of vulnerability on behavior and also to analyze the implementationand impact of risk management strategies, internal or external to the household. The first chapter concentrates on the effect of exposure to tenure insecurity in Angola on saving behavior. It states that households without document are not able to accumulate precautionary saving. This behavior of self-Coverage only occurs with cumulated risks. The second chapter focuses on the decision-Making within the household for the choice of diversification strategies. The allocation of women working time in Senegal between domestic work and income generating activities is studied. A model of separate spheres with a transfer between spouses is validated. The low incidence of financial incentives and the importance of bargaining power are demonstrated. The last chapter analyzes the impact of external intervention on household vulnerability through a program which aims to develop access to energy services. Its impact is estimated on the nutrition of children. The results show a positive and progressive effect of the presence of the infrastructure on long- erm nutrition. The intensity of use reduces the short-Term malnutrition. A diffusion effect is also established. These three chapters allow to stress the inability of households to develop independent strategies against the vulnerability. Then they make out the need to develop market access in rural areas. Finally,the role of external intervention to provide management tools to households is underlined

Le paludisme et la pneumonie constituent encore des problèmes de santé publique dans les pays à faible revenu, dont Madagascar. Toutefois, si le paludisme a reçu plus d’attention et vu ses programmes de lutte renforcés depuis la création du Fonds mondial en 2002, la pneumonie quant à elle est souvent négligée. Cependant, depuis peu, l’Unicef, s’appuyant sur les résultats encourageants obtenus au niveau communautaire dans la lutte contre le paludisme, pousse à l’intégration du dépistage et de la prise en charge de la pneumonie au niveau communautaire. Pour appuyer ce plaidoyer, des études d’impact et de type coût-efficacité sont nécessaires pour vérifier que cette stratégie est bien efficace et efficiente. C’est l’objet du chapitre 4 de cette thèse qui étudie l’expérience pilote menée par l’Unicef dans le district d’Antalaha. Nous montrons que ce programme a eu un impact notable sur la prise en charge du paludisme et de la pneumonie. Toutefois, la qualité de cette prise en charge est encore remise en question. Cela indique que, avant de décider d’une mise à l’échelle, ce programme mérite d’être révisé pour l’améliorer. Outre la perte de bien-être, le paludisme et la pneumonie ont un coût financier d’abord, économique, ensuite. Un des arguments de plaidoyer est alors de montrer, s’il y en a, les effets économiques des deux maladies. C’est l’objet des chapitres 2 et 3 avec une application à Madagascar. Auparavant, le sous-bassement théorique du lien entre santé et revenu ou développement économique est présenté dans le premier chapitre. / Malaria and pneumonia remain a public health problem in low-income countries, including Madagascar. However, while malaria has received more attention and its control programs have been strengthened since the creation of the Global Fund in 2002, pneumonia is often neglected. Face on the encouraging results of malaria community case management, UNICEF wants to integrate pneumonia management at community level. To support this advocacy, the impact and the cost-effectiveness of this strategy must be known to verify that it is effective and efficient. This is the purpose of Chapter 4 of this thesis which studies the pilot experiment conducted by Unicef in the district of Antalaha. It is shown that this program has had a significant impact on the management of malaria and pneumonia. However, the quality of this care is questioned. This situation indicates that, before scaling up, this program should be revised to improve it. Besides the loss of well-being, malaria and pneumonia have a financial and economic cost. Therefore, the economic effects of the two diseases are shown in the chapters 2 and 3 concerning the case of Madagascar. Previously, the theoretical under-base of the link between health and economic development is presented in the first chapter.

This thesis, motivated by the paucity of previous research in this subject area, describes an attempt to better understand the extent of poverty in rural Scotland and how the factors associated with that poverty may differ in the rest of the country. By identifying factors showing association uniquely with rural as opposed to urban poverty so policy decisions on targeted rural poverty alleviation could be made. Few such factors appear to have been tested formally for their association with poverty in rural Scotland. Using data from British Household Panel Survey (BHPS) datasets I create an income-based measure to compare levels of poverty across the rurality domain for the general population and several sub-populations. I also test the levels of association that factors found in the literature exhibit with households being in poverty, entering poverty and exiting poverty in both rural and non-rural Scotland. In so doing I highlight some of the data limitations within BHPS, particularly in the number of households in the remote and rural categories of the Scottish Government rural classification system. Under the current Scottish Government rural classification system it is evident that poverty in rural Scotland is lower than in the rest of the country. However, in-work poverty and fuel poverty are significantly higher in rural Scotland, where fluctuations in household fuel prices also appear to have a much quicker impact on poverty levels and levels of workless households than in the rest of the country. This thesis identifies evidence that the current definition of rural Scotland excludes parts of Scotland typically described as rural, with the result that the high levels of poverty in these areas goes unreported in most rural poverty analysis. Areas for further research are suggested, as is an alternative regional typology that may better reflect differences in poverty related factors across Scotland.

This thesis investigates the sensitivity of derived monetary valuations of the well-being effects of non-market goods, by considering, in turn, the four components that contribute to these calculations. Comparisons are made to the current subjective well-being (SWB) literature by altering one component at a time in a willingness to pay (WTP) function, in addition to varying the estimator used when calculating WTP. The first component varied is the measure of income used; a more robust, up-to-date measure is proposed that takes into account household size, economies of scale and composition, plus other improvements over current income scaling approaches including equivalence scales. Secondly, anticipation and adaptation effects are examined, in order to allow for the dynamics of SWB in WTP valuations. Thirdly, due to the ordered nature of the dependent variable, the effects of both cardinal and ordinal models on WTP derivations are investigated. Such models include the ordered logit fixed effects (FE) model (see for example Das and Van Soest (1999), Ferrer-i-Carbonell and Frijters (2004) and Baetschmann et al. (2011)). The final input to be varied is whether income endogeneity is accounted for. A control function approach is used in this case. A key finding is that all four inputs in the WTP calculation contribute significantly to the estimated WTP values. However, the degree to which each input influences the variation in WTP values differs substantially. The three main contributing factors to WTP variations are the income variable chosen, anticipation and adaptation effects, and controlling for endogeneity. Additionally, this thesis proposes a new way to define WTP that is also valid for ordered estimators. Whilst the standard WTP approach relies simply on coefficient ratios at a point in time, the method proposed here uses the finding that statistically significant anticipation and adaptation effects, along with adaptation to all non-market events (except for unemployment) suggest that there are concerns with taking WTP values as yearly valuations that assume constant effects on SWB. By instead defining WTP as the summation of the value of all WTP effects over all lag and lead effect periods, the total value of an event can be calculated. This definition presents further weaknesses of the original method by showing that because of significant lag and lead effects for events such as divorce and widowhood, these events have substantially larger WTP values than first thought. This leads to the major finding in this study that rank orders are not preserved when controlling for income endogeneity, even when comparing two model specifications that are identical in all other respects. Therefore, despite absolute WTP valuations appearing more similar for linear and ordered estimators when a more appropriate model specification is in place, the rank orders are affected. This finding argues against papers such as Powdthavee and van den Berg (2011) that find that rank orders are preserved for WTP valuations when modelling SWB. In conclusion, given rank orders are generally not preserved when a small change is made in the model specification, the validity of the WTP method is significantly reduced. Finally, the above methodology is applied to education, with the main contribution to the education literature being that the positive effects on SWB from education only exist in terms of lead effects.

This dissertation attempts to integrate the household and children more fluidly into measures of well-being in the past. In part one, I develop a Monte Carlo simulation to test some of the assumptions of Allen’s welfare ratio methodology. These included his assumptions that family size was constant over time, that there were no female-headed households and that women and children did not participate in the labour force. After all of the adjustments, it appears that Allen’s welfare ratios underestimate the welfare ratios of a demographically representative group of families, especially if women and children’s labour force participation is included. However, the predicted distributions also highlight the struggles of agricultural labourers, who are given separate consideration. Even the average agricultural labourers’ family with women and children working would have had to rely of self- provisioning, gleaning, poor relief or the extension of the working year to make ends meet at the poorest point in their family life cycle. Part two adjusts Floud et al.’s estimates of calorie availability in the English economy from 1700 to 1909 for the costs of digestion, pregnancy and lactation. Taken together, these three additional costs reduced the amount calories available by around 15 per cent in 1700 but only by 5 per cent in 1909 because of the changing composition of the English diet. Part three presents a new adaptive framework for studying changes in children’s growth patterns over time and a new methodology, longitudinal growth studies, for measuring gender disparities in health in the past. An adaptive framework for understanding growth provides a more parsimonious explanation for the vast catch-up growth achieved by slave children in the antebellum American South. The slave children were only able to achieve this catch-up growth because they were programmed for a tall height trajectory by relatively good conditions in utero. Finally, impoverished girls experienced greater catch-up growth than boys in two schools in late-nineteenth century Boston, USA and early-twentieth century London, suggesting that girls were deprived relative to boys before entering these institutions.