O núcleo tegmental rostromedial (RMTg) é uma estrutura relé GABAérgica entre a habênula lateral (LHb) e a área tegmental ventral (VTA), que também recebe projeções diretas da LHb. Para detalhar a topografia das projeções da LHb para o RMTg e VTA, injeções de um traçador anterógrado foram depositadas na LHb. A origem das projeções da LHb para o RMTg e VTA foi confirmada com injeções de um traçador retrógrado, no RMTg ou VTA. Além disso, comparamos a posição topográfica dos neurônios marcados no RMTg após injeções na VTA, com os axônios marcados, vindas da LHb. Nossos dados revelaram que as projeções da LHb estão organizadas de maneira topográfica, com projeções para o RMTg, se originando da LHb lateral e as projeções para a VTA da LHb medial. No RMTg, axônios oriundos da LHb foram observados pertos de neurônios que se projetam para a VTA, formando aposições com esses neurônios. Os resultados indicam que as projeções da LHb para o RMTg e VTA originam-se de diferentes regiões da LHb e provam a existência de uma via bisináptica que conecta a LHb com a VTA via o RMTg. / The rostromedial segmental nucleus (RMTg) is a GABAergic relay between the lateral habenula (LHb) and the ventral tegmental area (VTA), which also receives direct projections from the LHB. To detail the topography of LHb projections to the RMTg and VTA, injections of an anterograde tracer were made into the LHb. The origin of LHb projections to the RMTg and VTA was then confirmed by injections of a retrograde tracer into the RMTg or VTA. Additionally, we compared the topographic position of RMTg neurons labeled from injections in the VTA with that of axons labeled from the LHb. Our data revealed that LHb projections are organized in a topographic manner, with projections to the RMTg emerging from the lateral LHb and those to the VTA arising from the medial LHb. In the RMTg, LHb axons were found in register with VTA projecting neurons and were frequently apposed to the latter. Our findings indicate that LHb inputs to the RMTg and VTA arise from different divisions of the LHb and provide evidence for a disynaptic pathway that links the LHb to the VTA via the RMTg.

O presente trabalho investigou o efeito de uma história de cooperação sobre a escolha de um participante em cooperar ou trabalhar individualmente, na presença e ausência de custos. Os participantes trabalharam em um computador em uma tarefa para dois participantes, sendo que o computador simulava o desempenho do segundo participante. A cada tentativa, cada participante deveria escolher entre um cartão azul e um verde e a combinação de escolhas definia ganhos iguais ou desiguais para os participantes. Em função dos ganhos, uma resposta cooperativa foi definida como o participante escolher o cartão azul, uma resposta individual foi definida como o participante escolher o cartão verde. Isso porque o uso do cartão azul possibilitava que um dos participantes ganhasse mais em relação a uma matriz de ganhos menores, mas iguais. Os participantes foram expostos a cinco fases: Fase de Equidade, Fase de Iniquidade Favorável sem Custos, Fase de Iniquidade Desfavorável sem Custos, Fase de Iniquidade Favorável com Custos e Fase de Iniquidade Desfavorável sem Custos. O computador escolheu o cartão azul em todas as rodadas e fases do estudo e a escolha do cartão verde produzia 20 pontos para o Participante e para o computador em todas as fases do estudo. Na Fase de Equidade (10 rodadas) a escolha pelo cartão azul produzia 100 pontos para o participante e para o computador. Na Fase de Iniquidade Favorável sem Custos (16 rodadas) a escolha pelo cartão azul produzia 100 pontos para o participante e 20 para o computador. Na Fase de Iniquidade Desfavorável sem Custos (16 ou 32 rodadas) a escolha pelo cartão azul produzia 20 pontos para o participante e 100 para o computador. Na Fase de Iniquidade Favorável com Custos (16 rodadas) a escolha pelo cartão azul produzia 100 pontos para o participante e 10 para o computador. Na Fase de Iniquidade Desfavorável com Custos (16 ou 32 rodadas) a escolha pelo cartão azul produzia 10 pontos para o participante e 100 para o computador. Os participantes foram divididos em dois grupos, que diferiam quanto a ordem em que foram expostos ao custo. Nos dois grupos, a ultima fase do estudo tinha o dobro de rodadas das demais do estudo. Os resultados indicam que o efeito do custo variou entre participantes e também dependeu da ordem em que ele era introduzido: quanto mais cedo o custo foi introduzido, maior foi efeito em diminuir a escolha pelo cartão azul (cooperar). Os resultados também mostram sinais claros de aversão a iniquidade favorável e desfavorável. Alguns participantes produzem consistentemente a iniquidade desfavorável, o que desafia modelos formais de aversão a iniquidade / The present study investigated the effect of a history of cooperation on the choice of a participant in cooperating or working individually, in the presence and absence of costs. Participants worked on one computer in a two-person task, with the computer simulating the performance of the second participant. At each try, each participant should choose between a blue and a green card and the combination of choices defined equal or unequal gains for participants. Due to gains, a cooperative response was defined as the participant choosing the blue card, an individual response was defined as the participant choosing the green card. This was because the use of the blue card enabled one of the participants to earn more against an array of smaller but equal gains. Participants were exposed to five phases: Fairness Phase, Favorable Iniquity Phase without Costs, Unfavorable Iniquity Phase without Costs, Favorable Iniquity Phase with Costs and Unfavorable Iniquity Phase without Costs. The computer chose the blue card in all rounds and phases of the study and the choice of the green card produced 20 points for the Participant and the computer in all phases of the study. In the Fairness Phase (10 rounds) the choice for the blue card produced 100 points for the participant and for the computer. In the Favorable Iniquity Phase without Costs (16 rounds) the choice for the blue card produced 100 points for the participant and 20 points for the computer. In the Unfavorable Iniquity Phase without Costs (16 or 32 rounds) the choice for the blue card produced 20 points for the participant and 100 points for the computer. In Favorable Iniquity Phase with Costs (16 rounds) the choice for the blue card produced 100 points for the participant and 10 points for the computer. In the Unfavorable Iniquity Phase with Costs (16 or 32 rounds) the choice for the blue card produced 10 points for the participant and 100 points for the computer. Participants were divided into two groups, which differed in the order in which they were exposed to cost. In both groups, the last phase of the study had twice as many rounds as the rest of the study. The results indicate that the effect of cost varied between participants and also depended on the order in which it was introduced: the earlier the cost was introduced, the greater the effect was to decrease the choice by the blue card (cooperate). The results also show clear signs of aversion to favorable and unfavorable iniquity. Some participants consistently produce unfavorable iniquity, which challenges formal models of aversion to iniquity

Thesis advisor: Alicia Munnell / Thesis advisor: Tony Webb / Risk level of investments helps to determine investment return in the long run. Consequently, it is important to understand how investors determine their acceptable level of risk. Previous studies have suggested that women have a lower risk tolerance in investing than men. This is troubling because it means that women are likely to make lower returns on investments than men. This difference in acceptable risk could lead to income inequality between men and women during retirement as people rely on wealth generated from investments made during their lifetime to live during this stage of life. This study seeks to explain what motivates women to choose their acceptable level of investment risk by expanding on the models of previous studies, which are believed to be overly simplistic in their treatment of gender. / Thesis (BA) — Boston College, 2008. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Economics. / Discipline: College Honors Program.

A comercialização da energia elétrica por parte de empresas geradoras que já possuem suas usinas construídas é um tema de grande relevância no setor. A dificuldade em definir a estratégia de venda desta energia, dentre as opções disponíveis no atual modelo regulatório, torna necessário o desenvolvimento de metodologias e ferramentas que auxiliem na tomada de decisão, contabilizando as expectativas e riscos destas decisões. A metodologia com ferramental associado apresentada neste trabalho foi desenvolvida com base em conceitos amplamente utilizados no mercado financeiro para a formação de portfólio de ativos, aliados ao conceito basilar de utilidade das geradoras de energia elétrica, permitindo quantificar a predisposição à tomada de risco e a estruturação de informações públicas dos agentes do setor para a definição de perfis de geradores em relação à estratégia de venda de energia. A contribuição central deste trabalho reside na proposta de uma metodologia que define a melhor estratégia de participação em leilões de energia existente para geradores. / The energy trading activity for Generation Companies (Gencos) owning operating existing power plants is a topic of great relevance in the industry. The difficulty to define the energy selling strategy, given all available options in the actual regulatory model, makes necessary the development of methodologies and tools for decision making support, accounting the expectations and risks embedded in these decisions. The methodology and associated computational tool presented in this work was developed based on concepts widely used in the financial market for assets portfolio composition, the Gencos utility, making feasible to quantify the predisposition of risktaking, and the structuring of public information from the players involved for the definition of generators profiles in relation to the strategy of selling energy. The main contribution of this work lies on the validation of one methodology that defines the Gencos best strategy participation in the auctions designed for trading the existing power plants energy production.

O hipotálamo modula comportamentos relacionados à motivação, recompensa e punição através de projeções para a área tegmental ventral (VTA), o núcleo dorsal da rafe (DR) e o núcleo tegmental rostromedial (RMTg). Nesse estudo, investigamos através de métodos de rastreamento retrógrado as entradas hipotalâmicas da VTA, do DR e do RMTg e, se neurônios hipotalâmicos individuais inervam mais do que uma dessas regiões. Também determinamos uma possível assinatura GABAérgica ou glutamatérgica das aferências hipotalâmicas, através de rastreamento retrógrado combinado com métodos de hibridação in situ. Observamos que VTA, DR e RMTg recebem um padrão bastante semelhante de entradas hipotalâmicas originando de neurônios de projeção glutamatérgicas e GABAérgicas, a maioria deles (> 90%) inervando somente um desses três alvos. Nossos achados indicam que entradas hipotalâmicas são importantes fontes de sinais homeostáticos para a VTA, o DR e o RMTg. Eles exibem um alto grau de heterogeneidade que permite de excitar ou inibir as três estruturas de forma independente ou em conjunto. / The hypothalamus modulates behaviors related to motivation, reward and punishment via projections to the ventral tegmental area (VTA), dorsal raphe nucleus (DR), and rostromedial tegmental nucleus (RMTg). In this study we investigated by retrograde tracing methods hypothalamic inputs to the VTA, DR, and RMTg, and whether individual hypothalamic neurons project to more than one of these structures. We also determined a possible GABAergic or glutamatergic phenotype of hypothalamic afferents, by combining retrograde tracing with in situ hybridization methods. We found that VTA, DR, and RMTg receive a very similar set of hypothalamic afferents originating from glutamatergic and GABAergic hypothalamic projection neurons, the majority of them (> 90%) only innervating one of these structures. Our findings indicate that hypothalamic inputs are important sources of homeostatic signals for the VTA, DR, and RMTg. They exhibit a high degree of heterogeneity which permits to activate or inhibit the three structures either independently or jointly.

Extensive studies show that risk has a large impact on investment decisions. In addition, studies also show that risk behavior varies between men and women, where women tend to behave more risk averse. The purpose of this study is to examine how private investors make their investment decisions under risk but also to see if there are differences between men and women. The methods used in this research consists of a web survey that has been distributed via social media and interviews, to hear how private investors reason about investment decisions. The result from the web survey show that age and income does not affect investment decisions or their risk behavior. Neither does their own assessed willingness to take risk or knowledge in investments. The women in this research consider themselves to be more risk averse than men. However, when testing for their actual risk behavior, results show that women take more risk than men. Therefore, there are differences in investment decisions between women and men. / Tidigare forskning visar på att risk har en stor betydelse vid investeringsbeslut. Vissa studier menar även på att det föreligger en skillnad i kvinnor och mäns riskbenägenhet, där kvinnor anses vara mer riskaverta än män. Syftet med denna studie är att undersöka hur småsparare fattar sina investeringsbeslut under risk. Med hänsyn till tidigare studier har författarna även ett delsyfte att undersöka om och hur riskbenägenheten skiljer sig mellan kön. Studien har använt enkätundersökning samt intervjuer för att både ha tillgång till stora mängder data, men även för att fördjupa sig i det som enkäten inte kan besvara. Resultatet från enkätundersökningen visar att ålder och inkomst inte påverkar investeringsbeslut, samtidigt som intervjuerna säger det motsatta. Respondenternas självuppskattade riskbenägenhet och ansedda kunskap har heller ingen påverkan på deras investeringsbeslut. Kvinnorna i studien anger en lägre uppskattad riskbenägenhet än män samtidigt som de, i motsats till tidigare studier, agerar mer risksökande. Därmed föreligger det s

This thesis studies the labour supply with aspiration-based reference-dependent preferences. The first contribution of the thesis is the theoretical modelling of behavioural contract theory. In Chapter 1, I modify the classical principal-agent model with uncertainty and moral hazard by replacing the Expected Utility preferences of the agent with chance theory preferences (Schmidt and Zank, 2013). Chance theory agents are primarily concerned with the sure wage they can obtain, i.e., the certain component in their contract, as they treat increments in bonuses markedly different to similar changes in sure wages. Similar to the classical predictions, our agents' optimal contracts are contingent payment schemes, however, they differ with respect to the level of the sure wage. I also contrast my predictions to those of the model of Herweg et al. (2010), who assume agents with expectation-based loss-averse preferences. The other contribution of this thesis is the empirical support for the theory of aspiration-based reference-dependent preferences with field data in education economics. In Chapter 2, I study aspiration-based reference-dependent preferences in undergraduate students' performance and effort provision. Students' reference points are set as their targeted grades. I extend a two-period economics-of-education model (Krohn and O'Connor, 2005) by proposing an additional utility function that is based on the difference between the realised grade and targeted grade. I design surveys and collect data by following a group of undergraduate students at the University of Manchester for two semesters of a full academic year with a two-period panel. My results provide evidence for students' reference-dependent preferences in two ways: first, a significant jump in students' proxied utility of grade is found at the reference point, which also implies students are loss averse. Second, the reference point positively affects students' effort provision. I further study the formation of the reference point and its variation over time. My results suggest that students partially update their past realised results into the formation of reference points. Further, the relative change of their reference points depends on the achievement of the past period reference point.

While new agricultural technologies may lead to substantial yield improvements, the take-up rates in developing countries have frequently been low. There are many possible reasons why a farmer might refrain from adopting a new technology, and literature has pointed to several possible reasons in different settings. A key area for research is to understand what policies could encourage higher adoption rates. This thesis studies the research question by using a case study of fertiliser adoption in cocoa farming in Ghana. Chapter I investigates whether returns to fertiliser in cocoa farming are high and whether farmers' adoption decisions can be explained by comparative advantage. Chapter I uses data from Ghana to measure the returns to fertiliser using a correlated random model and static and dynamic panel models of homogeneous returns to fertiliser. The estimated returns in different models are positive, high and strongly significant statistically. The chapter also presents a correlated random effects model of heterogeneous technology, which allows for farmer-specific comparative advantage. The effect of the comparative advantage is found not to be statistically significant. Chapter II explores the fertiliser investment decisions and risk preferences of Ghanaian cocoa farmers in a framed field experiment. The experimental subjects decided whether to invest in fertiliser, and the fertiliser return depended on a stochastic weather realisation. An inexpensive index insurance scheme with a positive level of basis risk was found to have a minor positive effect on the fertiliser take-up, but this effect was statistically insignificant. An expensive index insurance scheme with no basis risk was found to have a substantial positive effect, and this effect was strongly significant. The experimental findings suggest that farmers are willing to pay for an index insurance if it successfully shields them from income variability. Chapter III investigates the effect of trust and of an ambiguous environment on fertiliser investments under index insurance. These two behavioural factors were studied by means of a framed field experiment conducted with Ghanaian cocoa farmers. The subjects had an option to invest in a package of fertiliser bundled with index insurance with a positive level of basis risk. The returns depended both on the subjects ́ investment choices and a stochastic weather realization. The key ingredient of the study was that for different subjects, the nature of the basis risk was framed differently. Substantially fewer subjects adopted fertiliser when possible losses of fertiliser investment were framed as resulting from the insurer ́s failure to meet its contract obligations, compared with an alternative in which the losses were framed as resulting from a mismatch between their own weather realizations and those on which the index insurance was based. A large negative effect on fertiliser investments was also found in treatments with either a small or large ambiguity regarding the exact level of basis risk. Both negative treatment effects were strongly significant. This may suggest that technologies with which farmers are relatively more experienced are more likely to be adopted under index insurance schemes. The overall experimental findings provide evidence that trust and ambiguity may be significant factors other than basis risk, limiting the effectiveness of index insurance in promoting agricultural innovation.

A comercialização da energia elétrica por parte de empresas geradoras que já possuem suas usinas construídas é um tema de grande relevância no setor. A dificuldade em definir a estratégia de venda desta energia, dentre as opções disponíveis no atual modelo regulatório, torna necessário o desenvolvimento de metodologias e ferramentas que auxiliem na tomada de decisão, contabilizando as expectativas e riscos destas decisões. A metodologia com ferramental associado apresentada neste trabalho foi desenvolvida com base em conceitos amplamente utilizados no mercado financeiro para a formação de portfólio de ativos, aliados ao conceito basilar de utilidade das geradoras de energia elétrica, permitindo quantificar a predisposição à tomada de risco e a estruturação de informações públicas dos agentes do setor para a definição de perfis de geradores em relação à estratégia de venda de energia. A contribuição central deste trabalho reside na proposta de uma metodologia que define a melhor estratégia de participação em leilões de energia existente para geradores. / The energy trading activity for Generation Companies (Gencos) owning operating existing power plants is a topic of great relevance in the industry. The difficulty to define the energy selling strategy, given all available options in the actual regulatory model, makes necessary the development of methodologies and tools for decision making support, accounting the expectations and risks embedded in these decisions. The methodology and associated computational tool presented in this work was developed based on concepts widely used in the financial market for assets portfolio composition, the Gencos utility, making feasible to quantify the predisposition of risktaking, and the structuring of public information from the players involved for the definition of generators profiles in relation to the strategy of selling energy. The main contribution of this work lies on the validation of one methodology that defines the Gencos best strategy participation in the auctions designed for trading the existing power plants energy production.

O presente trabalho investigou o efeito de uma história de cooperação sobre a escolha de um participante em cooperar ou trabalhar individualmente, na presença e ausência de custos. Os participantes trabalharam em um computador em uma tarefa para dois participantes, sendo que o computador simulava o desempenho do segundo participante. A cada tentativa, cada participante deveria escolher entre um cartão azul e um verde e a combinação de escolhas definia ganhos iguais ou desiguais para os participantes. Em função dos ganhos, uma resposta cooperativa foi definida como o participante escolher o cartão azul, uma resposta individual foi definida como o participante escolher o cartão verde. Isso porque o uso do cartão azul possibilitava que um dos participantes ganhasse mais em relação a uma matriz de ganhos menores, mas iguais. Os participantes foram expostos a cinco fases: Fase de Equidade, Fase de Iniquidade Favorável sem Custos, Fase de Iniquidade Desfavorável sem Custos, Fase de Iniquidade Favorável com Custos e Fase de Iniquidade Desfavorável sem Custos. O computador escolheu o cartão azul em todas as rodadas e fases do estudo e a escolha do cartão verde produzia 20 pontos para o Participante e para o computador em todas as fases do estudo. Na Fase de Equidade (10 rodadas) a escolha pelo cartão azul produzia 100 pontos para o participante e para o computador. Na Fase de Iniquidade Favorável sem Custos (16 rodadas) a escolha pelo cartão azul produzia 100 pontos para o participante e 20 para o computador. Na Fase de Iniquidade Desfavorável sem Custos (16 ou 32 rodadas) a escolha pelo cartão azul produzia 20 pontos para o participante e 100 para o computador. Na Fase de Iniquidade Favorável com Custos (16 rodadas) a escolha pelo cartão azul produzia 100 pontos para o participante e 10 para o computador. Na Fase de Iniquidade Desfavorável com Custos (16 ou 32 rodadas) a escolha pelo cartão azul produzia 10 pontos para o participante e 100 para o computador. Os participantes foram divididos em dois grupos, que diferiam quanto a ordem em que foram expostos ao custo. Nos dois grupos, a ultima fase do estudo tinha o dobro de rodadas das demais do estudo. Os resultados indicam que o efeito do custo variou entre participantes e também dependeu da ordem em que ele era introduzido: quanto mais cedo o custo foi introduzido, maior foi efeito em diminuir a escolha pelo cartão azul (cooperar). Os resultados também mostram sinais claros de aversão a iniquidade favorável e desfavorável. Alguns participantes produzem consistentemente a iniquidade desfavorável, o que desafia modelos formais de aversão a iniquidade / The present study investigated the effect of a history of cooperation on the choice of a participant in cooperating or working individually, in the presence and absence of costs. Participants worked on one computer in a two-person task, with the computer simulating the performance of the second participant. At each try, each participant should choose between a blue and a green card and the combination of choices defined equal or unequal gains for participants. Due to gains, a cooperative response was defined as the participant choosing the blue card, an individual response was defined as the participant choosing the green card. This was because the use of the blue card enabled one of the participants to earn more against an array of smaller but equal gains. Participants were exposed to five phases: Fairness Phase, Favorable Iniquity Phase without Costs, Unfavorable Iniquity Phase without Costs, Favorable Iniquity Phase with Costs and Unfavorable Iniquity Phase without Costs. The computer chose the blue card in all rounds and phases of the study and the choice of the green card produced 20 points for the Participant and the computer in all phases of the study. In the Fairness Phase (10 rounds) the choice for the blue card produced 100 points for the participant and for the computer. In the Favorable Iniquity Phase without Costs (16 rounds) the choice for the blue card produced 100 points for the participant and 20 points for the computer. In the Unfavorable Iniquity Phase without Costs (16 or 32 rounds) the choice for the blue card produced 20 points for the participant and 100 points for the computer. In Favorable Iniquity Phase with Costs (16 rounds) the choice for the blue card produced 100 points for the participant and 10 points for the computer. In the Unfavorable Iniquity Phase with Costs (16 or 32 rounds) the choice for the blue card produced 10 points for the participant and 100 points for the computer. Participants were divided into two groups, which differed in the order in which they were exposed to cost. In both groups, the last phase of the study had twice as many rounds as the rest of the study. The results indicate that the effect of cost varied between participants and also depended on the order in which it was introduced: the earlier the cost was introduced, the greater the effect was to decrease the choice by the blue card (cooperate). The results also show clear signs of aversion to favorable and unfavorable iniquity. Some participants consistently produce unfavorable iniquity, which challenges formal models of aversion to iniquity