Thesis advisor: Arthur Lewbel / Thesis advisor: S Anukriti / In this dissertation, I attempt to better understand the inner workings of the household: Do parents favor certain types of children? When do parents decide to have their children work? How can we identify inequality within the household? These issues are fundamental to economic development and closely related to individual welfare. However, studying these questions is difficult since the household is in many ways a blackbox to economists; consumption data is typically collected at the household level, and concepts like bargaining power are not observable. My research examines these questions in a variety of different contexts in the developing world. In Chapter 1, I test for consumption inequality between foster and non-foster children in Sub-Saharan Africa. In Chapter 2, I examine the relationship between child labor and fertility in Nigerian households. Lastly, I study the identification of intrahousehold inequality in collective households in Chapter 3. Chapter 1: In “Consumption Inequality Among Children: Evidence from Child Fostering in Malawi", I study how resources are allocated among foster and non- foster children in Malawi. Child fostering is widespread in parts of Africa and the wellbeing of these children, who may be particularly vulnerable to impoverishment, is not well known. However, identifying individual-level consumption is difficult, since goods are shared and consumption is measured at the household level. Recent work on intrahousehold resource allocation has inferred child consumption from household- level spending on child-specific goods (e.g., child clothing). This literature is often dependent on the existence of goods in the data that are consumed exclusively by a particular type of person in the household. These studies are therefore limited by the level of assignability of goods within the consumption survey. Stated differently, to identify inequality between foster and non-foster children using existing techniques, I would need to observe expenditure on a good that is consumed separately by foster and non-foster children. Because I do not, I develop a new methodology using the collective framework to measure consumption inequality between foster and non-foster children. I find little evidence of inequality between foster and non-foster children. I then divide foster children by whether the child is orphaned, and I find that orphan-foster child consumption is 23 percent less than non-orphan foster child consumption. The results of this paper suggest that policymakers should design programs to improve the relative standing of orphan-foster children in the household. The methodological contribution of this paper is applicable to other contexts as intrahousehold inequality among children is widespread. Chapter 2: In “Child Labor Laws and Household Fertility Decision: Evidence from Nigeria" I study the Child Rights Act of Nigeria (CRA). In 2003, the Nigerian National Assembly implemented this law, which codified existing child labor standards and dramatically increased the penalties for employing children. I exploit the Child Rights Act to both understand the employment consequences of a child labor legislation, and to analyze the effect of lowering the economic value of children on fertility rates. Identification comes from variation in the timing of when each Nigerian state adopted the law, and from variation in the law’s age restrictions. Consistent with recent theoretical and empirical evidence, I find the Child Rights Act increased child employment at both the intensive and extensive margins. I then model household fertility decisions to demonstrate that the demand for children is increasing in child wages and therefore influenced by changes in the child labor market. I empirically test the model implications by examining the effect of the Child Rights Act on fertility rates, but find little to no effect. Chapter 3: In “Identification of Resource Shares with Multiple Assignable Goods" (with Caitlin Brown and Rossella Calvi), we study intrahousehold inequality. We develop a new methodology using the collective framework to identify resource shares, defined as the fraction of household resources consumed by each household member. We build upon recent work by Dunbar, Lewbel, and Pendakur (2013) (DLP) who identify resource shares by observing how expenditure on a single private assignable good varies with household income and size. They achieve identification by making semi-parametric restrictions on preferences across either household members or household sizes. Because our data contain multiple private assignable goods, we are able to employ this additional data to weaken the DLP preference restrictions using a different approach, which we call “Differenced-Similar Across People" (D-SAP). Under D-SAP, preferences for the assignable goods are allowed to differ entirely across both household members. However, we introduce a weaker restriction that requires that preferences differ across people in a similar way across goods. / Thesis (PhD) — Boston College, 2018. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Economics.

Thesis advisor: Arthur Lewbel / My doctoral research comprises both structural empirical work in the field of household economics (Chapters 1 and 3) and reduced-form theoretical work in econometrics (Chapter 2). The first chapter quantifies consumption gains in the form of consumption expenditure savings for couples living together versus apart. Moreover, I comprehensively analyze the key drivers of heterogeneity in consumption gains across couples. The second chapter, which is joint work with Stefan Hoderlein, develops the first difference-in-differences model for binary choice outcome variables when treatment effects are heterogeneous. Finally, in the third chapter, I study the realized gains in consumption levels upon move-in from single to couple and move-out from couple to single, separately by gender. Chapter 1. In “Heterogeneity in Consumption Gains from Living Together as a Couple”, I estimate consumption gains from living together versus apart. Specifically, this chapter quantifies these gains from consumption economies of scale for married as well as unmarried cohabiting couples in the U.S. I also comprehensively analyze the determinants of heterogeneity in consumption gains. For this purpose, I extend a recent collective household model to incorporate heterogeneity in consumption economies of scale and perform structural estimation using data from the Panel Study of Income Dynamics (PSID). I find that couples living together save an average of 14 percent in annual consumption expenditures compared to their counterfactual spending when living apart. Moreover, older couples and homeowner couples experience higher consumption economies of scale and thus higher consumption gains. I do not detect marital status to be a determining factor. These results have implications for appropriate adjustment of poverty thresholds across households of different sizes. Chapter 2. In “Binary Choice Difference-in-Differences Model with Heterogeneous Treatment Effects”, we develop the first Difference-in-Differences Model for binary choice outcome variables when treatment effects are heterogeneous. Our main result establishes identification of the average treatment effect on the treated (ATT). Moreover, we present two extensions. First, we show identification of the joint distribution of the actual and counterfactual latent outcome variable in the treatment group. Second, we extend the basic model to allow for the inclusion of covariates. We suggest an estimator for the ATT and evaluate its finite sample properties with the help of Monte Carlo simulations. Chapter 3. In “Realized Consumption Gains from Living Together as a Couple by Gender”, I am among the first to analyze how consumption gains from living together as a couple are split between men and women and whether this varies by individual-level or couple-level observables. Understanding individual-level consumption gains is important for rationalizing marriage and cohabitation decisions on the micro-level, and marriage and cohabitation patterns on the macro-level. I use the extended collective household model from Chapter 1 and data from the PSID to estimate male and female realized consumption gains from moving in as a couple and moving out of a couple. Average realized consumption gains upon move-in are positive for women and negative for men. This reverses for dissolving couples. Lastly, individuals who move in with their spouse have higher realized consumption gains than individuals who decide to cohabit without a marriage certificate. / Thesis (PhD) — Boston College, 2018. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Economics.

This thesis is concerned with a fundamental unit of the economy: Households. Even in advanced economies, upwards of 70% of the population live in households composed of multiple people. A large number of decisions are taken at the level of the household, that is to say, they are taken jointly by household members: How to raise children, how much and when to work, how many cartons of milk to purchase. How these decisions are made is therefore of great importance for the people who live in them and for their well-being.But precisely because household members make decisions jointly it is hard to know how they come about and to what extent they benefit individual members. This is why households are often viewed as unique decision makers in economics. Even if they contain multiple people, they are treated as though they were a single person with a single set of preferences. This unitary approach is often sufficient and can be a helpful simplification. But in many situations it does not deliver an adequate description of household behavior. For instance, the unitary model does not permit the study of individual wellbeing and inequality inside the household. In addition, implications of the unitary model have been rejected repeatedly in the demand literature.Bargaining models offer an alternative where household members have individual preferences and come to joint decisions in various ways. There are by now a great number of such models, all of which allow for the study of bargaining power, a measure of the influence a member has in decision making. This concept is important because it has implications for the welfare of individuals. If one household member’s bargaining power increases, the household’s choices will be more closely aligned with that member’s preferences, ceteris paribus.The three chapters below can be divided into two parts. The first part consists of Chapter 1, which looks to detect the influence of intra-household bargaining in a specific set of consumption choices: Consumption of the arts. The research in this chapter is designed to measure aspects of the effect of bargaining power in this domain, but does not seek to quantify bargaining power itself or to infer economic well-being of household members.Precisely this last point, however, is the focus of the second part of the thesis, consisting of Chapters 2 and 3. These focus specifically on the recovery of one measure of bargaining power, the resource share. Resource shares have the advantage of being interpretable in terms of economic well-being, which is not true of all such measures. They are estimated as part of structural models of household demand. These models are versions of the collective model of household decision making.Pioneered by Chiappori (1988) and Apps and Rees (1988), the collective model has become the go-to alternative to unitary approaches, where the household is seen as a single decision-making unit with a single well-behaved utility function. Instead, the collective model allows for individual utility functions for each member of the household. The model owes much of its success to the simplicity of its most fundamental assumption: That whatever the structure of the intra-household bargaining process, outcomes are Pareto-efficient. This means that no member can be made better off, without making another worse off. Though the model nests unitary models as special cases, it does have testable implications.The first chapter of the thesis is entitled “Household Decisions on Arts Consumption” and is joint work with Caterina Mauri, who has also collaborated with me on many other projects in her capacity as my girlfriend. In it, we explore the role of intra-household bargaining in arts consumption. We do this by estimating demand for various arts and cultural events such as the opera or dance performances using a large number of explanatory variables. One of these variables plays a special role. This variable is a distribution factor, meaning that it can be reasonably assumed to affect consumption only through the bargaining process, and not by modifying preferences. Such variables play an important role in the household bargaining literature. Here, three such variables are used. Among them is the share of household income that is contributed by the husband, the canonical distribution factor.The chapter fits into a literature on drivers of arts consumption, which has shown that in addition to such factors as age, income and education, spousal preferences and characteristics are important in determining how much and which cultural goods are consumed. Gender differences in preferences in arts consumption have also been shown to be important and to persist after accounting for class, education and other socio-economic factors (Bihagen and Katz-Gerro, 2000).We explore to what extent this difference in preferences can be used to shed light on the decision process in couples’ households. Using three different distribution factors, we infer whether changes in the relative bargaining power of spouses induce changes in arts consumption.Using a large sample from the US Current Population Survey which includes data on the frequency of visits to various categories of cultural activities, we regress atten- dance rates on a range of socio-economic variables using a suitable count data model.We find that attendance by men at events such as the opera, ballet and other dance performances, which are more frequently attended by women than by men, show a significant influence of the distribution factors. This significant effect persists irrespec- tively of which distribution factor is used. We conclude that more influential men tend to participate in these activities less frequently than less influential men, conditionally on a host of controls notably including hours worked.The second chapter centers around the recovery of resource shares. This chapter is joint work with Denni Tommasi, a fellow PhD student at ECARES. It relies on the collective model of the household, which assumes simply that household decisions are Pareto-efficient. From this assumption, a relatively simple household problem can be formulated. Households can be seen as maximizers of weighted sums of their members’ utility functions. Importantly the weights, known as bargaining weights (or bargaining power), may depend on many factors, including prices. The household problem in turn implies structure for household demand, which is observed in survey data.Collective demand systems do not necessarily identify measures of bargaining power however. In fact, the ability to recover such a measure, and especially one that is useful for welfare analysis, was an important milestone in the literature. It was reached by (Browning et al. 2013) (henceforth BCL), with a collective model capable of identi- fying resource shares (also known as a sharing rule). These shares provide a measure of how resources are allocated in the household and so can be used to study intra- household consumption inequality. They also take into account that households gen- erate economies of scale for their members, a phenomenon known as a consumption technology: By sharing goods such as housing, members of households can generate savings that can be used elsewhere.Estimation of these resource shares involves expressing household budget shares functions of preferences, a consumption technology and a sharing rule, each of which is a function of observables, and letting the resulting system loose on the data. But obtaining such a demand system is not free. In addition to the usual empirical speci- fications of the various parts of the system, an identifying assumption has to be made to assure that resource shares can be recovered in estimation. In BCL, this is the assumption that singles and adult members of households share the same preferences. In Chapter 2, however, an alternative assumption is used.In a recent paper, Dunbar et al. (2013) (hereafter DLP) develop a collective model based on BCL that allows to identify resource shares using assumptions on the simi- larity of preferences within and between households. The model uses demand only for assignable goods, a favorite of household economists. These are goods such as mens’ clothing and womens’ clothing for which it is known who in a household consumes them. In this chapter, we show why, especially when the data exhibit relatively flat Engel curves, the model is weakly identified and induces high variability and an im- plausible pattern in least squares estimates.We propose an estimation strategy nested in their framework that greatly reduces this practical impediment to recovery of individual resource shares. To achieve this, we follow an empirical Bayes method that incorporates additional (or out-of-sample) information on singles and relies on mild assumptions on preferences. We show the practical usefulness of this strategy through a series of Monte Carlo simulations and by applying it to Mexican data.The results show that our approach is robust, gives a plausible picture of the house- hold decision process, and is particularly beneficial for the practitioner who wishes to apply the DLP framework. Our welfare analysis of the PROGRESA program in Mexico is the first to include separate poverty rates for men and women in a CCT program.The third Chapter addresses a problem similar to the one discussed in Chapter 2. The goal, again, is to estimate resource shares and to remedy issues of imprecision and instability in the demand systems that can deliver them. Here, the collective model used is based on Lewbel and Pendakur (2008), and uses data on the entire basket of goods that households consume. The identifying assumption is similar to that used by BCL, although I allow for some differences in preferences between singles and married individuals.I set out to improve the precision and stability of the resulting estimates, and so to make the model more useful for welfare analysis. In order to do so, this chapter approaches, for the first time, the estimation of a collective household demand system from a Bayesian perspective. Using prior information on equivalence scales, as well as restrictions implied by theory, tight credible intervals are found for resource shares, a measure of the distribution of economic well-being in a household. A modern MCMC sampling method provides a complete picture of the high-dimensional parameter vec- tor’s posterior distribution and allows for reliable inference.The share of household earnings generated by a household member is estimated to have a positive effect on her share of household resources in a sample of couples from the US Consumer Expenditure survey. An increase in the earnings share of one percentage point is estimated to result in a shift of between 0.05% and 0.14% of household resources in the same direction, meaning that spouses partially insure one another against such shifts. The estimates imply an expected shift of 0.71% of household resources from the average man to the average woman in the same sample between 2008 and 2012, when men lost jobs at a greater rate than women.Both Chapters 2 and 3 explore unconventional ways to achieve gains in estimator precision and reliability at relatively little cost. This represents a valuable contribution to a literature that, for all its merits in complexity and ingenious modeling, has not yet seriously endeavored to make itself empirically useful. / Doctorat en Sciences économiques et de gestion / info:eu-repo/semantics/nonPublished

Esse estudo tem como objetivo investigar o comportamento da oferta de trabalho dos cônjuges brasileiros e verificar o grau de adequação desse em relação a um modelo específico dentro da abordagem coletiva (\'collective models\'). O modelo coletivo de oferta de trabalho com fatores distributivos oferece uma estrutura teórica para interpretar o processo decisório intra-familiar e seus resultados, as alocações de consumo e oferta de trabalho das famílias, que são Pareto eficientes por hipótese. Fatores distributivos são variáveis que afetam a decisão sobre oferta de trabalho, mas não tem impactos sobre as preferências nem a restrição orçamentária das famílias. As informações relativas à amostra de famílias brasileiras foram obtidas a partir da PNAD e da Estatística de Registros Civis, ambas para o ano de 2004. Os resultados não rejeitam as restrições derivadas do modelo coletivo, tanto em sua forma geral quanto na versão restrita pela imposição de preferências egoístas. Além disso, as variáveis adotadas como fatores distributivos, sex-ratio e \'participação em divórcios\', influenciam, de forma significativa e condizente com a teoria, a oferta de trabalho de maridos e esposas. / This paper has as objective to investigate the Brazilian spouses\' labor supply behavior and to empirically check the adequacy of a specific collective model. The collective labor supply model with distribution factors offers a theoretical structure to interpret the intra-household decision process and its results, the families\' choices of consumption and labor supply, who are Pareto efficient. Distribution factors are variables that affect the labor supply decision, but do not have impacts on the preference relations nor the budget constraint of the families. The sample of Brazilian families had been gotten from the \"PNAD\" and \"Estatística de Registros Civis\", for the year of 2004. The results do not reject the restrictions derived from the collective model, neither in its general form nor in the egoisti preferences form. Moreover, distribution factors, sex-ratio and \'participação em divórcios\', are found to affect labor supply of husbands and wives in the directions predicted by the theory and to be statistically significant.

For many years, Cd-110 has been considered the classic example of a vibrational nucleus within both the Collective Model and the Interacting Boson Model (IBM). As a vibrational nucleus, Cd-110 exhibits multi-phonon states. Recent studies on other cadmium isotopes have shown a breakdown of vibrational motion at the three-phonon level. The latest study on Cd-112 suggests that some of these excitations may instead result from intruder bands. The study through internal conversion electrons is important to investigate intruder structures in Cd-110, using the enhanced E0 transitions between intruder states and spherical phonon states as a signature. The nuclear structure of Cd-110 has been studied with In-110 beta decay through internal conversion electrons performed at TRIUMF using the 8pi spectrometer. The level scheme of Cd-110 through internal conversion electron transitions was constructed using the electron-gamma coincidence matrix. The sub-shell ratios and multipolarities are determined and compared with the evaluated data set. The absolute internal conversion coefficients for some mixed transitions were determined using an internal calibration efficiency for Si(Li) detector and relative efficiency for HPGe detector. The 396 keV and 708 keV E0 transitions have been observed between intruder and spherical phonon states. The E0 transition strength of 0.115(71) was determined for 708.21 keV line.

Esse estudo tem como objetivo investigar o comportamento da oferta de trabalho dos cônjuges brasileiros e verificar o grau de adequação desse em relação a um modelo específico dentro da abordagem coletiva (\'collective models\'). O modelo coletivo de oferta de trabalho com fatores distributivos oferece uma estrutura teórica para interpretar o processo decisório intra-familiar e seus resultados, as alocações de consumo e oferta de trabalho das famílias, que são Pareto eficientes por hipótese. Fatores distributivos são variáveis que afetam a decisão sobre oferta de trabalho, mas não tem impactos sobre as preferências nem a restrição orçamentária das famílias. As informações relativas à amostra de famílias brasileiras foram obtidas a partir da PNAD e da Estatística de Registros Civis, ambas para o ano de 2004. Os resultados não rejeitam as restrições derivadas do modelo coletivo, tanto em sua forma geral quanto na versão restrita pela imposição de preferências egoístas. Além disso, as variáveis adotadas como fatores distributivos, sex-ratio e \'participação em divórcios\', influenciam, de forma significativa e condizente com a teoria, a oferta de trabalho de maridos e esposas. / This paper has as objective to investigate the Brazilian spouses\' labor supply behavior and to empirically check the adequacy of a specific collective model. The collective labor supply model with distribution factors offers a theoretical structure to interpret the intra-household decision process and its results, the families\' choices of consumption and labor supply, who are Pareto efficient. Distribution factors are variables that affect the labor supply decision, but do not have impacts on the preference relations nor the budget constraint of the families. The sample of Brazilian families had been gotten from the \"PNAD\" and \"Estatística de Registros Civis\", for the year of 2004. The results do not reject the restrictions derived from the collective model, neither in its general form nor in the egoisti preferences form. Moreover, distribution factors, sex-ratio and \'participação em divórcios\', are found to affect labor supply of husbands and wives in the directions predicted by the theory and to be statistically significant.

This dissertation consists of three essays studying the effects of collective household decisions on early childhood development from both empirical and theoretical perspectives. The first chapter outlines the dissertation, by presenting the motivations, methods, conclusions, and policy implications for the entire dissertation. Chapter two examines early childhood development using a collective model with children's cognitive production. We jointly estimate the home input demand with children's cognitive production functions based on a simultaneous equations model. Biases are considered that are caused by the non-random selection of time inputs and possible correlations across inputs and outcomes functions. A direct measure of time inputs relying on children's time diaries from the Child Development Supplement of the Panel Study of Income Dynamics (PSID-CDS) has been constructed. We thereby relax the assumption that there is no difference between parental time spent on children and leisure. Our results show that parental time inputs, especially the active time interacting with children's daily activities, have substantial effects on both children's math and reading test scores. The time inputs vary across parents' age, race, and eduction levels. In chapter three, we conduct a standard Blinder-Oaxaca decomposition to evaluate the role of home inputs in the black-white test score gaps based on the empirical model presented in chapter two. Aside from the finding that children's ability accounts for a large proportion of the differences, we find that home inputs can also explain a significant portion of the gap. When the maternal time is equalized at the average levels of white children, the racial differences in children's reading and math test scores can be closed by approximately 30%-50%. The last chapter extends a collective model with household production to the general equilibrium framework. We concentrate on the impacts of a global bargaining power shift within the household on children's cognitive achievement, especially on those who live with single mothers. The model shows that a global bargaining power change in favor of the female may not necessarily be beneficial to the children living with their single mothers. An increase of female's market equilibrium wage rate as a result of reduced labor supply by married women may induce single mothers to work longer hours, spend less time with children, and compensate them with more monetary investment compared with the case when the equilibrium wage rate stays constant. / Ph. D.

Neste trabalho estudamos a influência que os aditivos decanol e o anestésico local tetracaína (TTC) exercem sobre a estrutura de sistemas micelares. Foram estudadas particularmente a influência do decanol na estrutra das micelas do surfactante aniônico dodecil sulfato de sódio (SLS) e da TTC na estrutura micelar do SLS e do surfactante zwiteriônico N-hexadecil-N, N-dimetil-3-amônio-1-propanosulfonato (HPS). O estudo de soluções micelares concentradas (razão molar água:SLS, Mw= 45,2) do sistema binário SLS/água e do sistema ternário SLS/decanol/água por difração de raios X nas vizinhanças das transições de fase isotrópica (I) SETA hexagonal (Halfa) líqüido-cristalina indicam que existe um empacotamento das micelas em uma ordem hexagonal local na fase I do sistema binário, e a fase Halfa tem empacotamento típico de objetos finitos/rígidos. No sistema ternário, em contraste, o empacotamento é relaxado através de um crescimento micelar induzido pelo decanol e a fase Halfa, que ocorre a uma concentração molar decanol:SLS, Md = 0,20, tem um comportamento típico de objetos infinitos/flexíveis. Uma seqüência intrigante de fases HalfaSETA nemática cilíndrica (Nc) a Md= 0,25 foi também investigada e é atribuída a um efeito combinado de crescimento micelar e mudança na rigidez da micela, com aumento da quantidade de decanol. O subseqüente aumento em Md leva o sistema à transição de fase Nc SETA nemática discótica (Nd) (Md= 0,38), acompanhada de uma mudança de forma micelar cilindro SETA disco. A influência do decanol em soluções isotrópicas mais diluídas (Mw= 144,0) foi estudada por espalhamento de raios X a baixos ângulos (SAXS) e analisada através das funções distribuição de distâncias p(r) e da distribuição de densidades eletrônicas rô(r). Os resultados mostram que micelas esferoidais crescem por influência do decanol e mudam de forma esferoide SETA cilindro a Md= 0,20 e cilindro SETA disco a Md APROXIMADAMENTE IGUAL A 0,40. Portanto, tornou-se evidente que a evolução de forma micelar do SLS pela influência do decanol é governada pela energia de curvatura da interface polar/apolar, uma vez que o decanol prefere localizar-se em interfaces planas, e que as transições de fase líqüido-cristalinas dependem dessas mudanças, associadas a efeitos de ordem estrutural em soluções concentradas. A influência da TTC em micelas aquosas de SLS e HPS foi estudada pelas técnicas espectroscópicas de fluorescência e ressonância paramagnética eletrônica (RPE) e por SAXS. Os resultados de fluorescência indicam que a droga é incorporada nas micelas, sendo que a TTC protonada se localiza mais próxima à interface polar/a polar das micelas, enquanto que a desprotonada penetra mais o interior hidrofóbico. Os resultados de RPE concordam com estas observações e indicam um aumento na organização molecular das micelas de SLS com a incorporação do anestésico local. Este aumento é mais pronunciado para micelas compostas por SLS e TTC carregada. Por outro lado, não foi observada nenhuma alteração significativa na organização molecular de micelas de HPS por influência da TTC. Através dos resultados de SAXS não foi observada nenhuma alteração na dimensão e na forma micelar por adição gradual de TTC neutra em SLS ou carregada em HPS, até a razão molar TTC:SLS, \'M IND. TTC\'= 0,30. Já os resultados de SAXS para os sistemas compostos por SLS e TTC protonada evidenciam um crescimento de micelas elipsoidais prolatas com anisometria v APROXIMADAMENTE IGUAL A 1,5 a \'M IND. TTC\'= 0 para v APROXIMADAMENTE IGUAL A 1,8 a \'M IND. TTC\'= 0,20 e 0,30. Os resultados são discutidos em termos de alteração das forças envolvidas na formação micelar (eletrostáticas e hidrofóbicas) e da própria estrutura molecular da TTC. / The influence of the aditives decanol and the local anaesthetic tetracaine on the micellar structure of the anionic surfactant sodium dodecyl sulfate (SLS) and zwiterionic N-hexadecyl-N, N-dymethyl-3-ammonio-1-propane-sulfonate (HPS) has been studied. The study of concentrated micellar solutions (water:SLS molar ratio, Mw= 45.2) of the binary system SLS/water and ternary SLS/water/decanol through X-ray diffraction dose to the liquid-crystalline isotropic (I) \'SETA\' hexagonal (Halfa) phase transition indicates a local micellar hexagonal packing in the I phase in the binary system, whereas the Halfa phase exhibits a packing typic of finite/rigid objects. On the other hand, the ternary system presents a more relaxed packing through a micellar growth induced by decanol, and the Halfa phase, which occurs at the decanol:SLS molar ratio, Md= 0.20 has got a typical infinite/flexible objects behaviour. An intriguing Halfa \'SETA\' cilindric nematic (Nc) phase sequence was also investigated at Md= 0.25 and has been atributed to the combined effect of the micellar growth and change of rigidity with the increasing in decanol amount. A further increase in Md leads to the Nc \'SETA\' discotic nematic (Nd) transition (Md= 0.38), which is accompanied by the cylinder \'SETA\' disc change of form. The infiuence of decanol in more diluted solutions of SLS/water (Mw= 144.0) has been studied through small-angle X-ray scattering (SAXS) and analysed through the distance distribution function p(r) and electronic density distribution rô(r). The results show that the spheroidal micelles grow due to the influence of decanol, changing from spheroid to cylinder form at Md= 0.20 and from cylinder to disc at Md= 0.40. Therefore, it became evident that the evolution of the SLS micellar shape under the effect of decanol is dominated by the bending curvature energy from the polar/apolar interface, since the decanol prefers the flat interfaces, and the liquid-crystalline phase transitions depend on these changes of shape, associated to structural order effects in concentrated solutions. The influence of TTC on SLS and HPS micelles were studied through fluorescence and electronic paramagnetic resonance espectroscopic techniques as well as by SAXS. The fluorescence results indicate that the drug incorporates into the micelles in such a way that the protonated TTC is localized close to the polar/apolar interface, whereas the uncharged form penetrates deeper into the hydrophobic core, in SLS micelles. The EPR results agree with the above observation besides indicating an increase in the SLS micellar molecular organization as the local anaesthetic is incorporated. Such an increase is more pronounced for micelles composed of SLS and charged TTC. On the other hand, no meaningful alteration in the HPS micelles molecular organization was observed under the TTC influence. From the SAXS results, we have not detected any changes in the micellar dimension and shape by gradual addition of either neutral TTC in SLS or charged TTC in HPS up to the TTC:SLS molar ratio (\'M IND. TTC\') of 0.30. Conversely, the SAXS results for systems composed of SLS and charged TTC have shown a micellar growth of prolate ellipsoidal micelles from anisometry v APROXIMADAMENTE IGUAL A 1.5 at \'M IND. TTC\'= O to v APROXIMADAMENTE IGUAL A 1.8 at \'M IND. TTC\'= 0.20 and 0.30. The results are discussed in the view of alterations in the forces involved in the micellar auto-assembling (electrostatic and hydrophobic) and the TTC structure.

Neste trabalho estudamos a influência que os aditivos decanol e o anestésico local tetracaína (TTC) exercem sobre a estrutura de sistemas micelares. Foram estudadas particularmente a influência do decanol na estrutra das micelas do surfactante aniônico dodecil sulfato de sódio (SLS) e da TTC na estrutura micelar do SLS e do surfactante zwiteriônico N-hexadecil-N, N-dimetil-3-amônio-1-propanosulfonato (HPS). O estudo de soluções micelares concentradas (razão molar água:SLS, Mw= 45,2) do sistema binário SLS/água e do sistema ternário SLS/decanol/água por difração de raios X nas vizinhanças das transições de fase isotrópica (I) SETA hexagonal (Halfa) líqüido-cristalina indicam que existe um empacotamento das micelas em uma ordem hexagonal local na fase I do sistema binário, e a fase Halfa tem empacotamento típico de objetos finitos/rígidos. No sistema ternário, em contraste, o empacotamento é relaxado através de um crescimento micelar induzido pelo decanol e a fase Halfa, que ocorre a uma concentração molar decanol:SLS, Md = 0,20, tem um comportamento típico de objetos infinitos/flexíveis. Uma seqüência intrigante de fases HalfaSETA nemática cilíndrica (Nc) a Md= 0,25 foi também investigada e é atribuída a um efeito combinado de crescimento micelar e mudança na rigidez da micela, com aumento da quantidade de decanol. O subseqüente aumento em Md leva o sistema à transição de fase Nc SETA nemática discótica (Nd) (Md= 0,38), acompanhada de uma mudança de forma micelar cilindro SETA disco. A influência do decanol em soluções isotrópicas mais diluídas (Mw= 144,0) foi estudada por espalhamento de raios X a baixos ângulos (SAXS) e analisada através das funções distribuição de distâncias p(r) e da distribuição de densidades eletrônicas rô(r). Os resultados mostram que micelas esferoidais crescem por influência do decanol e mudam de forma esferoide SETA cilindro a Md= 0,20 e cilindro SETA disco a Md APROXIMADAMENTE IGUAL A 0,40. Portanto, tornou-se evidente que a evolução de forma micelar do SLS pela influência do decanol é governada pela energia de curvatura da interface polar/apolar, uma vez que o decanol prefere localizar-se em interfaces planas, e que as transições de fase líqüido-cristalinas dependem dessas mudanças, associadas a efeitos de ordem estrutural em soluções concentradas. A influência da TTC em micelas aquosas de SLS e HPS foi estudada pelas técnicas espectroscópicas de fluorescência e ressonância paramagnética eletrônica (RPE) e por SAXS. Os resultados de fluorescência indicam que a droga é incorporada nas micelas, sendo que a TTC protonada se localiza mais próxima à interface polar/a polar das micelas, enquanto que a desprotonada penetra mais o interior hidrofóbico. Os resultados de RPE concordam com estas observações e indicam um aumento na organização molecular das micelas de SLS com a incorporação do anestésico local. Este aumento é mais pronunciado para micelas compostas por SLS e TTC carregada. Por outro lado, não foi observada nenhuma alteração significativa na organização molecular de micelas de HPS por influência da TTC. Através dos resultados de SAXS não foi observada nenhuma alteração na dimensão e na forma micelar por adição gradual de TTC neutra em SLS ou carregada em HPS, até a razão molar TTC:SLS, \'M IND. TTC\'= 0,30. Já os resultados de SAXS para os sistemas compostos por SLS e TTC protonada evidenciam um crescimento de micelas elipsoidais prolatas com anisometria v APROXIMADAMENTE IGUAL A 1,5 a \'M IND. TTC\'= 0 para v APROXIMADAMENTE IGUAL A 1,8 a \'M IND. TTC\'= 0,20 e 0,30. Os resultados são discutidos em termos de alteração das forças envolvidas na formação micelar (eletrostáticas e hidrofóbicas) e da própria estrutura molecular da TTC. / The influence of the aditives decanol and the local anaesthetic tetracaine on the micellar structure of the anionic surfactant sodium dodecyl sulfate (SLS) and zwiterionic N-hexadecyl-N, N-dymethyl-3-ammonio-1-propane-sulfonate (HPS) has been studied. The study of concentrated micellar solutions (water:SLS molar ratio, Mw= 45.2) of the binary system SLS/water and ternary SLS/water/decanol through X-ray diffraction dose to the liquid-crystalline isotropic (I) \'SETA\' hexagonal (Halfa) phase transition indicates a local micellar hexagonal packing in the I phase in the binary system, whereas the Halfa phase exhibits a packing typic of finite/rigid objects. On the other hand, the ternary system presents a more relaxed packing through a micellar growth induced by decanol, and the Halfa phase, which occurs at the decanol:SLS molar ratio, Md= 0.20 has got a typical infinite/flexible objects behaviour. An intriguing Halfa \'SETA\' cilindric nematic (Nc) phase sequence was also investigated at Md= 0.25 and has been atributed to the combined effect of the micellar growth and change of rigidity with the increasing in decanol amount. A further increase in Md leads to the Nc \'SETA\' discotic nematic (Nd) transition (Md= 0.38), which is accompanied by the cylinder \'SETA\' disc change of form. The infiuence of decanol in more diluted solutions of SLS/water (Mw= 144.0) has been studied through small-angle X-ray scattering (SAXS) and analysed through the distance distribution function p(r) and electronic density distribution rô(r). The results show that the spheroidal micelles grow due to the influence of decanol, changing from spheroid to cylinder form at Md= 0.20 and from cylinder to disc at Md= 0.40. Therefore, it became evident that the evolution of the SLS micellar shape under the effect of decanol is dominated by the bending curvature energy from the polar/apolar interface, since the decanol prefers the flat interfaces, and the liquid-crystalline phase transitions depend on these changes of shape, associated to structural order effects in concentrated solutions. The influence of TTC on SLS and HPS micelles were studied through fluorescence and electronic paramagnetic resonance espectroscopic techniques as well as by SAXS. The fluorescence results indicate that the drug incorporates into the micelles in such a way that the protonated TTC is localized close to the polar/apolar interface, whereas the uncharged form penetrates deeper into the hydrophobic core, in SLS micelles. The EPR results agree with the above observation besides indicating an increase in the SLS micellar molecular organization as the local anaesthetic is incorporated. Such an increase is more pronounced for micelles composed of SLS and charged TTC. On the other hand, no meaningful alteration in the HPS micelles molecular organization was observed under the TTC influence. From the SAXS results, we have not detected any changes in the micellar dimension and shape by gradual addition of either neutral TTC in SLS or charged TTC in HPS up to the TTC:SLS molar ratio (\'M IND. TTC\') of 0.30. Conversely, the SAXS results for systems composed of SLS and charged TTC have shown a micellar growth of prolate ellipsoidal micelles from anisometry v APROXIMADAMENTE IGUAL A 1.5 at \'M IND. TTC\'= O to v APROXIMADAMENTE IGUAL A 1.8 at \'M IND. TTC\'= 0.20 and 0.30. The results are discussed in the view of alterations in the forces involved in the micellar auto-assembling (electrostatic and hydrophobic) and the TTC structure.

La thèse porte sur des modèles économiques en présence d’externalités. En suivant Laffont (1988), nous donnons la définition suivante d’externalité.“Effet indirect” signifie que l’effet est créé par un agent économique différent de celui qui est affecté, et que l’effet n’est pas produit par l’intermédiaire du système de prix. Par conséquence, le système des prix ne joue que le rôle d’égaler à l’équilibre l’offre globale et la demande globale. La définition ci-dessus montre que la présence d’effets externes nécessite une nouvelle description des caractéristiques des agents, c’est-à-dire des préférences individuelles, des ensembles de consommation et des ensembles de production des producteurs. La thèse se compose de trois chapitres. Le premier chapitre étudie les restrictions de testabilité d’un modèle spécifique avec des externalités et des biens publics. Dans le deuxième chapitre et le troisième chapitre, nous considérons un modèle d’équilibre général avec des externalités au niveau des préférences individuelles et des ensembles de production des producteurs. Dans le deuxième chapitre nous traitons l’existence d’un équilibre concurrentiel en utilisant un approche différentiable, et dans le troisième chapitre nous donnons un résultat de régularité. Dans le Chapitre 2, nous considérons un modèle d’économie de propriété privée avec des externalités de consommation et de production. En utilisant une approche différentiable, nous prouvons que l’ensemble des équilibres concurrentiels avec des consommations et des prix strictement positifs est non vide et compact. Dans le Chapitre 3, nous considérons des économies de propriété privée avec externalités de consommation et de production. Nous étudions des conditions suffisantes pour la régularité générique de ces économies. / We study the testability implications of public versus private consumption in col-lective models of group consumption. The distinguishing feature of our approach is that we start from a revealed preference characterization of collectively rational behavior. Remarkably, we find that assumptions regarding the public or private nature of specific goods do have testability implications, even if one only observes the aggregate group consumption. In fact, these testability implications apply as soon as the analysis includes three goods and four observations. This stands in sharp contrast with existing results that start from a differential characterization of collectively rational behavior. In our opinion, our revealed preference approach obtains stronger testability conclusions because it focuses on a global characterization of collective rationality, whereas the differential approach starts from a local characterization.We consider a general model of private ownership economies with consumption and production externalities. Each firm is characterized by a technology described by a transformation function. Each household is characterized by a utility function, the shares on firms’ profit and an initial endowment of commodities. Describing equlib-ria in terms of first order conditions and market clearing conditions, and using a homotopy approach based on the seminal work by Smale (1974), under differentiability and boundary conditions, we prove the non-emptiness and the compactness of the set of competitive equilibria with consumptions and prices strictly positive.We consider a general equilibrium model of private ownership economy with con-sumption and production externalities. Each firm is owned by the households and it is characterized by a technology described by a transformation function. Each household is characterized by a utility function, the shares on the firms profits and an endowment of commodities. The choices of all agents (households and firms) affect utility functions and production technologies. Showing by an example that basic assumptions are not enough to guarantee a regularity result in the space of initial endowments, we provide sufficient conditions for the regularity in the space of endowments and perturbations of the transformation functions.