[pt] A globalização dos mercados financeiros das últimas décadas trouxe ao centro da discussão de finanças internacionais o conceito de risco-país. A importância do risco para a economia de um país está relacionada ao fato de que, em um ambiente de alta mobilidade de capital, ele acaba sendo um importante balizador da taxa de juros doméstica. Para que se possa compreender a evolução do risco de um país, medido pelo spread de seus títulos no mercado internacional, não basta entender a influência das características específicas dos países, mas é fundamental também avaliar o papel dos choques internacionais. Dentro deste arcabouço, o objetivo central desta dissertação é avaliar de maneira mais precisa o papel das variáveis externas na determinação dos spreads dos países emergentes. Mostraremos que para entender os choques externos sobre os spreads emergentes não basta observar os movimentos da taxa de juros livre de risco, como se supõe na literatura tradicional, mas também é preciso fazer considerações acerca da aversão ao risco dos investidores internacionais, e do contágio entre os países emergentes durante períodos de crise. / [en] The globalization in the financial markets during the last decades brought the concept of country risk to the center of the discussion in international finance. The importance of country risk is related to the fact that, in a high capital mobility environment, it becomes a important determinant of the domestic interest rate. To understand the evolution of the risk of a country, measured by the spread of its bonds in the international markets, it is important not only to comprehend the influence of its specific fundamentals, but also to evaluate the role of the external shocks. In this framework, the central goal of this dissertation is to evaluate more accurately the role of the external variables in the determination of the spreads of the emerging countries. It will be shown that to understand the external shocks it is not enough to observe only the movements of the free risk interest rate, as the traditional literature assume, but it is also necessary to take into account the risk aversion of the international investors, and the contagion between emerging economies during crisis time.

已開發國家中，無論個人或是法人所擁有之財富大多透過金融中介機構管理，因此，財富委由他人管理衍生出現代資本市場中重要的委託關係。委託人與基金管理人產生委任契約時，也必然產生代理問題，即雙方利益不一致所額外增加的成本。為降低代理成本，於委任合約加入對管理人下檔投資風險的要求成為降低代理成本的重要機制。本研究因此探討當基金管理人面對契約存在最低報酬要求時，如何進行最適資產配置決策，並同時分析下檔風險限制改變時對管理人投資行為的影響。研究結果顯示，委任合約增加經理人最低保證收益時，基金管理人傾向增加持股，而經理人風險趨避程度增加時，將減少風險性股票資產，進而持有債券；如果投資目標收益於受委託期間皆不改變，將造成經理人持有債券組合以規避下檔風險，同時卻喪失追求資本利得。 / In most developed countries, financial wealth is not managed directly by the investors, but through a financial intermediary. Hence, the delegated portfolio management is one of the most important principal-agency relationships in the current economy. In addition to that, the principal-agency relationships between the investor and portfolio manager must produce agency cost. In order to reduce these costs, the mandates in the contract become an important factor in reducing the principal-agent problem in a delegated portfolio management framework. In this research, we study how fund managers do asset allocation when they face some guaranteed returns and the relationships between the choices of mandates and the behavior of fund managers. We suppose that the objective of the delegated fund managers is to maximize the expected utility of wealth of the long-term fund at the end of each period and fund managers also have to fulfill some constrains given at the beginning. Finally, we explain how fund managers do optimal asset allocation by our model and some numerical analysis.

Taiwan, an island with outstanding economic miracle, has deeply depended on international trades to increase economic growth and national wealth. There are many successful companies, including listed enterprises and SME, manufacturing and marketing Made-in-Taiwan products all over the world through international trade and commerce. Therefore, undoubtedly the power international trade is one of our strength and plays a key role on stimulating economy as well as elevating the living standard of people. . To compete with other international exporters, Taiwanese exporters must provide not only products with good quality and reasonable price, but also offer competitive payment terms to further strive for new clients and strengthen individual competitiveness. This is a recent trend of International Trade. From the risk-free payment term, such as- T/T Advance to O/A 90 days after shipment, Taiwanese exporters suffered both political risk and credit risk. Not to mention cash flow risk and exchange rate risk that normally appears during transaction. Remembered financial crisis in 2007, market failed and malfunctioned at that time. As for corporate side, individual companies faced difficulties of continuously operation. Some even seriously went bankruptcy during that time. In this circumstance, Taiwanese exporters, even successfully won the orders, could not receive the payment on time from foreign buyers. Some of them may even suffered huge loss because of intentional disputes or buyer’s closedown. Therefore, it goes without saying that risk aversion is becoming an important issue for Taiwanese companies to survive. There would be three major financial tools being introduced for risk aversion with three case studies. Each of them has its special features and functions by different needs. How and why does Taiwanese exporter choose and leverage for risk aversion will be explained and discussed. The purpose of this paper is to find out the solutions for Taiwanese exporters to reduce risk of international trade as well as increase competitiveness in the foreign trade and grow the economy as contribution in the long run.

L'addiction correspond à un désordre psychobiologique caractérisé par une tendance chronique à la rechute, et implique des processus d'ordre motivationnels et émotionnels qui mettent en jeu des phénomènes d'apprentissage et de mémoire affective. Chez le toxicomane abstinent, la présentation de situations environnementales précédemment associées à l'expérience du sevrage des opiacés est capable d'induire un intense désir pour la drogue (craving), et il a été proposé que ces stimuli conditionnés pourraient précipiter la rechute en réactivant les circuits neuronaux qui sont mis en jeu de manière inconditionnée par le sevrage. Dans ce contexte, nous avons entrepris la caractérisation de la composante motivationnelle du sevrage des opiacés en utilisant des modèles comportementaux (sevrage précipité par des faibles doses de naloxone chez le rat morphino-dépendant, réexposition à des stimuli environnementaux précédemment associés au sevrage dans un modèle d'aversion de place conditionnée) qui permettent d'évaluer les propriétés aversives et motivationnelles du sevrage, aussi bien sur le versant inconditionné que conditionné. Nous avons ainsi recherché les substrats neurobiologiques impliqués dans ces phénomènes en traçant de manière extensive les circuits neuronaux recrutés, en terme de localisation et de populations neuronales, par une approche de neuroanatomie fonctionnelle utilisant la détection du marqueur de réactivité neuronale c-fos par hybridation in situ. D'une manière générale, nos résultats montrent que les substrats neuronaux sous-jacents à la composante motivationnelle du sevrage – qui incluent en particulier les structures de l'extended amygdala (noyau accumbens partie médiale shell, noyau du lit de la strie terminale et noyau central de l'amygdale) et les régions limbiques qui lui sont associées (noyau basolatéral de l'amygdale, hippocampe, septum latéral et aire tegmentale ventrale) – peuvent être dissociés d'un ensemble d'autres régions cérébrales qui sont en revanche impliquées dans l'expression de la symptomatologie somatique du sevrage. Au niveau de l'aire tegmentale ventrale (VTA), notre analyse phénotypique des neurones recrutés au cours du sevrage précipité par la naloxone (situation inconditionnée) et lors de la présentation de stimuli environnementaux associés au sevrage (situation conditionnée) montre une induction massive dans la population des interneurones GABAergiques. Bien qu'une telle activité GABAergique est supposée être capable d'inhiber en grande partie les neurones dopaminergiques, nous montrons également qu'une sous-population de neurones dopaminergiques de la VTA (environ 15%) est activée dans ces deux situations. Au niveau de l'amygdale, nos résultats montrent l'existence d'une double dissociation anatomique et fonctionnelle dans la réponse globale des noyaux central (CeA) et basolatéral (BlA) en terme d'expression de c-fos entre les situations inconditionnée et conditionnée. Dans le BlA, bien que le sevrage précipité par la naloxone induise une diminution de l'activité de la majorité des neurones efférents glutamatergiques, une sous-population de ces neurones montre une intense induction de l'ARNm c-fos. La réexposition aux stimuli conditionnés au sevrage provoque quant à elle une intense activation dans de nombreux neurones glutamatergiques du BlA. Dans les neurones GABAergiques du CeA, les réponses c-fos sont opposées aux réponses globales du BlA, puisque l'expression de c-fos dans ces neurones est augmentée dans la situation inconditionnée, alors qu'elle est diminuée dans la situation conditionnée. Nous proposons que le pattern d'expression de c-fos que nous détectons dans l'ensemble de ces structures limbiques pourrait refléter 1/ la mise en place de processus d'apprentissage associatif permettant d'encoder la valeur affective et motivationnelle des stimuli environnementaux associés au sevrage de la morphine, dans la situation inconditionnée, et 2/ le rappel et l'expression des associations mémorisées au cours du conditionnement, dans la situation conditionnée (mémoire du sevrage). Ainsi, sur la base de l'ensemble de nos résultats et de nombreuses données de la littérature, nous proposons un modèle fonctionnel pour la formation et le rappel de la mémoire du sevrage des opiacés.

A fundamental question in the neurobiological study of drug addiction concerns the mechanisms mediating the motivational effects of chronic drug withdrawal. According to one theory, drugs of abuse activate opposing motivational processes after both acute and chronic drug use. The negative experience of withdrawal is the opponent process of chronic drug use that drives relapse to drug-seeking and -taking, making the identification of the neurobiological substrates mediating withdrawal an issue of central importance in addiction research. In this thesis, I identify the involvement of the neurotransmitters dopamine (DA) and corticotropin-releasing factor (CRF) in the opponent motivational a- and b-processes occurring after acute and chronic nicotine administration. I report that acute nicotine stimulates an initial aversive a-process followed by a rewarding opponent b-process, and chronic nicotine stimulates a rewarding a-process followed by an aversive opponent b-process (withdrawal). These responses can be modeled using a place conditioning paradigm. I demonstrate that the acute nicotine a-process is mediated by phasic dopaminergic activity and the DA receptor subtype-1 (D1R) but not by tonic dopaminergic activity and the DA receptor subtype-2 (D2R) or CRF activity, and the opponent b-process is neither DA- nor CRF-mediated. I also demonstrate that the chronic nicotine a-process is DA- but not CRF-mediated, and that withdrawal from chronic nicotine (the b-process) decreases tonic but not phasic DA activity in the ventral tegmental area (VTA), an effect that is D2R- but not D1R-mediated. I show that a specific pattern of signaling at D1Rs and D2Rs mediates the motivational responses to acute nicotine and chronic nicotine withdrawal, respectively, by demonstrating that both increasing or decreasing signaling at these receptors prevents the expression of the conditioned motivational response. Furthermore, I report that the induction of nicotine dependence increases CRF mRNA in VTA DA neurons, and that blocking either the upregulation of CRF mRNA or the activation of VTA CRF receptors prevents the anxiogenic and aversive motivational responses to withdrawal from chronic nicotine. The results described in this thesis provide novel evidence of a VTA DA/CRF system, and demonstrate that both CRF and a specific pattern of tonic DA activity in the VTA are necessary for the aversive motivational experience of nicotine withdrawal.

This thesis consists of an introductory part and four self-contained papers related to individual financial behavior and risk-taking in financial markets. In Paper [I] we estimate within-family and community social interaction effects upon an individual’s stock market entry, participation, and exit decision. Interestingly, community sentiment towards the stock market (based on portfolio outcomes in the community) does not influence individuals’ likelihood to enter, while a positive sentiment increases (decreases) the likelihood of participation (exit). Overall, the results stress the importance of accounting for family social influence and highlight potentially important differences between family and community effects in individuals’ stock market participation. In Paper [II] novel evidence is provided indicating that the influence from family (parents and partners) and peer social interaction on individuals’ stock market participation vary over different types of individuals. Results imply that individuals’ exposure to, and valuation of, stock market related social signals are of importance and thus, contribute to the understanding of the heterogeneous influence of social interaction. Overall, the results are interesting and enhance the understanding of the underlying mechanisms of social interaction on individuals’ financial decision making. In Paper [III] the impact of divorce ­­­on individual financial behavior is empirically examined in a dynamic setting. Evidence that divorcing individuals increase their saving rates before the divorce is presented. This may be seen as a response to the increase in background risk that divorce produces. After the divorce, a negative divorce effect on individual saving rates and risky asset shares are established, which may lead to disparities in wealth accumulation possibilities between married and divorced. Women are, on average, shown to not adjust their precautionary savings to the same extent as men before the divorce. I also provide tentative evidence that women reduce their financial risk-taking more than men after a divorce, which could be a result of inequalities in financial positions or an adjustment towards individual preferences.   Paper [IV] provides novel empirical evidence that gender identity is of importance for individuals’ financial risk-taking. Specifically, by use of matching and by dividing male and females into those with “traditional” versus “nontraditional” gender identities, comparison of average risk-taking between groupings indicate that over a third (about 35-40%) of the identified total gender risk differential is explained by differences in gender identities. Results further indicate that risky financial market participation is 19 percentage points higher in groups of women with nontraditional, compared with traditional, gender identities. The results, obtained while conditioning upon a vast number of controls, are robust towards a large number of alternative explanations and indicate that some individuals (mainly women) partly are fostered by society, through identity formation and socially constructed norms, to a relatively lower financial risk-taking.

Les gérants de portefeuille pour compte de tiers sont souvent jugés par leur performance relative à celle d'un portefeuille benchmark. A ce titre, ils sont amenés très fréquemment à utiliser des modèles internes de "risk management" pour contrôler le risque de sous-performer le benchmark. Par ailleurs, ils sont de plus en plus nombreux à adopter une politique de rémunération incitative, en percevant une commission de sur-performance par rapport au benchmark. En effet, cette composante variable de leur rémunération leur permet d'augmenter leur revenu en cas de sur-performance sans contrepartie en cas de sous-performance. Or de telles pratiques ont fait récemment l'objet de nombreuses polémiques : la période récente de crise financière mondiale a fait apparaître certaines carences de plusieurs acteurs financiers en terme de contrôle de risque ainsi que des niveaux de prise de risque et de rémunération jugés excessifs. Cependant, l'étude des implications de ces pratiques reste un thème encore relativement peu exploré dans le cadre de la théorie classique des choix dynamiques de portefeuille en temps continu. Cette thèse analyse, dans ce cadre théorique, les implications de ces pratiques de "benchmarking" sur le comportement d'investissement de l'asset manager. La première partie étudie les propriétés de la stratégie dynamique optimale pour l'asset manager concerné par l'écart entre la rentabilité de son portefeuille et celle d'un benchmark fixe ou stochastique (sur ou sous-performance). Nous considérons plusieurs types d'asset managers, caractérisés par différentes fonctions d'utilité et qui sont soumis à différentes contraintes de risque de sous-performance. Nous montrons en particulier quel est le lien entre les problèmes d'investissement avec prise en compte de l'aversion à la sous-performance et avec contrainte explicite de "risk management". Dans la seconde partie, on s'intéresse à l'asset manager bénéficiant d'une rémunération incitative (frais de gestion variables, bonus de sur-performance ou commission sur encours additionnelle). On étudie, selon la forme de ses incitations financières et son degré d'aversion à la sous-performance, comment sa stratégie d'investissement s'écarte de celle de l'investisseur (ou celle de l'asset manager sans rémunération incitative). Nous montrons que le changement de comportement de l'asset manager peut se traduire soit par une réduction du risque pris par rapport à la stratégie sans incitation financière soit au contraire par une augmentation de celui-ci. Finalement, nous montrons en quoi la présence de contraintes de risque de sous-performance, imposées au gérant ou traduisant son aversion à la sous-performance, peut être bénéfique à l'investisseur donnant mandat de gestion financière.

Les disparités socio-spatiales sont à la fois une cause et une conséquence des inégalités sociales. Cette thèse interroge le rôle des inégalités sociales dans la formation et la correction des disparités socio-spatiales. Elle est composée de trois essais, qui éclairent différentes facettes de ce questionnement, faisant intervenir les migrations résidentielles et les politiques publiques. Le premier essai analyse la pertinence des orientations stratégiques nationales de la politique de développement rural à l'aune du débat philosophique sur la justice sociale. Il met en évidence le rôle que joue et que devrait jouer l'objectif de réduction des inégalités sociales dans la définition d'une politique agissant sur les disparités socio-spatiales. Les deux essais suivants montrent comment les inégalités sociales génèrent des disparités socio-spatiales par le biais des mobilités résidentielles de longues et de courtes distances. Le second essai étudie les effets du sentiment d'aversion à l'inégalité locale et de la politique de redistribution du revenu sur les mobilités et les disparités interrégionales, dans le cadre théorique de la Nouvelle Economie Géographique. Le dernier essai examine comment les inégalités sociales conditionnent les choix résidentiels et induisent une ségrégation socio-spatiale au sein des aires urbaines françaises, à l'aide de modèles économétriques de choix discrets

La crescente attenzione riguardo l’interconnessione tra agricoltura e aspetti ambientali così come la crescita di volatilità dei prezzi dei prodotti agricoli ha posto una nuova enfasi sull’introduzione di misure ambientali nella politiche agricole e sulla ricerca di nuovi strumenti di stabilizzazione del reddito degli agricoltori. La ricerca di questa tesi di dottorato si inserisce in questo contesto e analizza i contratti agro-ambientali, misure della Politica Agricola Comunitaria (PAC) in Unione Europea (UE), sotto una duplice prospettiva. Il primo lavoro di ricerca consiste in un’analisi degli effetti dell’adesione a tali contratti sulle scelte produttive e sulle perfomance economiche degli agricoltori in cinque Paesi dell’UE. I risultati indicano un’eterogeneità di questi effetti: in alcuni Paesi i contratti agro-ambientali sembrano essere più efficaci nel promuovere pratiche agricole sostenibili, così come in alcuni Paesi il pagamento compensativo agro-ambientale sembra non essere sufficiente a compensare la perdita di reddito dei partecipanti. Questo studio è stato condotto combinando il Propensity Score Matching con lo stimatore Difference-in-Differences. Il secondo lavoro di ricerca sviluppa una nuova proposta metodologica che incorpora il rischio in un framework di Programmazione Matematica Positiva (PMP). Il modello elaborato presenta caratteri innovativi rispetto alla letteratura sull’argomento e permette di stimare simultaneamente i prezzi ombra delle risorse, la funzione di costo non lineare dell’azienda agricola e un coefficiente di avversione al rischio specifico per ciascuna azienda. Il modello è stato applicato a tre campioni di aziende e i risultati delle stime testano la calibrazione del modello e indicano valori del coefficiente di avversione al rischio coerenti con la letteratura. Infine il modello è stato impiegato nella simulazione di diversi scenari al fine di verificare il ruolo potenziale di un contratto agro-ambientale come strumento di gestione del rischio a diversi livelli di volatilità dei prezzi agricoli. / The increasing attention to the relationship between agriculture and the environment and the rise in price volatility on agricultural markets has led to a new emphasis on agri-environmental policies as well as to a search for new risk management strategies for the farmer. The research objective of this PhD thesis is in line with this challenging context, since it provides an analysis of the EU agri-environmental schemes (AESs) from two viewpoints. First, an ex-post analysis aims at investigating the AESs for their traditional role as measures which encourage sustainable farming while compensating the farmer for the income foregone in five EU Member States. The effects of AESs participation on farmer’s production plans and economic performances differs widely across Member States and in some of them the environmental payment is not enough to compensate the income foregone of participants. This study has been performed by applying a semi-parametric technique which combines a Difference-in-Differences estimator with a Propensity Score Matching estimator. The second piece of research develops a new methodological proposal to incorporate risk into a farm level Positive Mathematical Programming (PMP) model. The model presents some innovations with respect to the previous literature and estimates simultaneously the resource shadow prices, the farm non-linear cost function and a farm-specific coefficient of absolute risk aversion. The proposed model has been applied to three farm samples and the estimation results confirm the calibration ability of the model and show values for risk aversion coefficients consistent with the literature. Finally different scenarios have been simulated to test the potential role of an AES as risk management tool under different scenarios of crop price volatility.

A fundamental question in the neurobiological study of drug addiction concerns the mechanisms mediating the motivational effects of chronic drug withdrawal. According to one theory, drugs of abuse activate opposing motivational processes after both acute and chronic drug use. The negative experience of withdrawal is the opponent process of chronic drug use that drives relapse to drug-seeking and -taking, making the identification of the neurobiological substrates mediating withdrawal an issue of central importance in addiction research. In this thesis, I identify the involvement of the neurotransmitters dopamine (DA) and corticotropin-releasing factor (CRF) in the opponent motivational a- and b-processes occurring after acute and chronic nicotine administration. I report that acute nicotine stimulates an initial aversive a-process followed by a rewarding opponent b-process, and chronic nicotine stimulates a rewarding a-process followed by an aversive opponent b-process (withdrawal). These responses can be modeled using a place conditioning paradigm. I demonstrate that the acute nicotine a-process is mediated by phasic dopaminergic activity and the DA receptor subtype-1 (D1R) but not by tonic dopaminergic activity and the DA receptor subtype-2 (D2R) or CRF activity, and the opponent b-process is neither DA- nor CRF-mediated. I also demonstrate that the chronic nicotine a-process is DA- but not CRF-mediated, and that withdrawal from chronic nicotine (the b-process) decreases tonic but not phasic DA activity in the ventral tegmental area (VTA), an effect that is D2R- but not D1R-mediated. I show that a specific pattern of signaling at D1Rs and D2Rs mediates the motivational responses to acute nicotine and chronic nicotine withdrawal, respectively, by demonstrating that both increasing or decreasing signaling at these receptors prevents the expression of the conditioned motivational response. Furthermore, I report that the induction of nicotine dependence increases CRF mRNA in VTA DA neurons, and that blocking either the upregulation of CRF mRNA or the activation of VTA CRF receptors prevents the anxiogenic and aversive motivational responses to withdrawal from chronic nicotine. The results described in this thesis provide novel evidence of a VTA DA/CRF system, and demonstrate that both CRF and a specific pattern of tonic DA activity in the VTA are necessary for the aversive motivational experience of nicotine withdrawal.