Health literacy and substance use in young Swiss men.

OBJECTIVES: The purpose of the present study was to describe health literacy and its association with substance use among young men. METHODS: The present study was part of the Cohort Study on Substance Use Risk Factors that included 11,930 Swiss males participating in initial screening from August 2010 to July 2011. Self-completed questionnaires covered use of three substances and three components of health literacy. RESULTS: Roughly 22 % reported having searched the Internet for health information and 16 % for information on substances over the past 12 months. At-risk and not at-risk users of alcohol (adjusted odds ratio (AOR) = 2.50 and 1.46), tobacco (AOR = 2.51 and 1.79) and cannabis (AOR = 4.86 and 3.53) searched for information about substances significantly more often via the Internet than abstainers. Furthermore, at-risk users reported better knowledge of risks associated with substance use and a marginally better ability to understand health information than abstainers. CONCLUSIONS: Substance users appear to be more informed and knowledgeable about the risks of substance use than non-users. Consequently, interventions that focus only on information provision may be of limited benefit for preventing substance use.

Prendre des risques, ça rapporte ? Conduites à risques et perception des risques chez des adolescents tout-venant

Risk taking and its association with substance use by adolescents are often studied among clinical populations. The behavior of non-clinical adolescent samples is less well-known. According to some scholars, the adoption of risk behaviors can be predicted by a function of perceptions of both benefits and risks of such behaviors. However, the literature is still controversial about their respective significance. In this study, a non-clinical sample of 221 adolescents, aged 14 to 20, completed two questionnaires: the RIPS-R to estimate risk taking behaviors as well as perception of the risks and benefits of such behaviors, and the DEP-ADO to measure substance use. Our results show a high annual prevalence of socially accepted risk behaviors (drinking alcohol, not studying for exams, smoking tobacco). However, socially repressed behaviors (brawling, vandalism) are very occasional and are associated with problematic substance use. Globally, engagement in risk behaviors is more closely linked with the perceptions of its benefits than the perception of its risks. Finally, limitations and implications of these results for research and prevention are provided. Les prises de risques et leur association avec la consommation de substances chez les adolescents ont souvent été étudiées auprès de populations cliniques. Le comportement des jeunes tout-venant est en revanche moins bien connu. Selon certains théoriciens, la participation à des conduites à risques peut être déterminée en fonction des perceptions de leurs bénéfices et dangers potentiels. Toutefois, la littérature ne s'accorde pas sur l'importance respective que ces perceptions revêtent. Dans cette étude, 221 adolescents tout-venant, âgés de 14 à 20 ans, ont complété deux questionnaires : le RIPS-R pour évaluer la prise de risques et leur perception en termes de risques et de bénéfices, et la DEP-ADO pour mesurer la consommation de substances. Les résultats mettent en évidence une prévalence annuelle élevée des comportements à risques socialement acceptables (boire de l'alcool, fumer du tabac). En revanche, les comportements réprimés socialement (bagarres, actes de vandalisme) s'avèrent très occasionnels et sont associés à la consommation problématique de substances. Globalement, c'est la perception des bénéfices qui est le plus fortement liée au fait d'adopter un comportement à risque. Finalement, les limites et les implications pratiques de ces résultats sont discutées. © 2010 Elsevier Masson SAS. Tous droits réservés.

Rôle des paramètres sociopolitiques et des connaissances dans la gestion des risques hydrologiques

Résumé Rôle des paramètres sociopolitiques et des connaissances dans la gestion des risques hydrologiques¦La recherche analyse (1) la mise en oeuvre de la gestion des risques hydrologiques et (2) les connaissances dont disposent les acteurs sur ces derniers, ainsi que (3) les interdépendances entre ces deux volets. Au total, trois études de cas ont été réalisées dont deux études régionales (ville de Berne, commune de Saillon) et une étude sur un acteur spécifique (les corporations de digues dans le canton de Berne). Les données empiriques ont été obtenues par des entretiens oraux semi-directifs et des enquêtes écrites.¦La gestion des risques hydrologiques est fortement influencée par des paramètres sociopolitiques, c'est-à-dire par les intérêts et les objectifs des acteurs, par les rapports de force entre ceux-ci ainsi que par les processus de négociation et de décision. Dans la pratique, les démarches de gestion se restreignent toutefois majoritairement aux aspects physiques, techniques et administratifs des risques hydrologiques. La dimension sociopolitique est ainsi négligée, ce qui est source de conflits qui ralentissent considérablement la planification de la protection contre les crues, voire la bloquent même complètement. La gestion des risques hydrologiques est en outre largement focalisée sur la réduction des aléas. Lés débats sur la vulnérabilité sont nettement plus rares bien qu'ils soient indispensables lorsqu'il s'agit de traiter les risques de façon holistique.¦Etant donné l'importance de la dimension sociopolitique et de la vulnérabilité, il est nécessaire que les démarches prévues dans la gestion des risques hydrologiques soient reconsidérées et adaptées. De plus, une meilleure intégration de tous les acteurs concernés est primordiale afin de trouver des solutions qui soient acceptables pour une majorité. Pour l'instant, le recours à des instruments de négociation est insuffisant.¦Les connaissances des risques hydrologiques et de leur gestion peuvent être classées en quatre répertoires (connaissances du système, de l'événement, de l'intervention et connaissances sociopolitiques) qui influent tous sur la réduction des risques. Parmi les facteurs les plus importants susceptibles de déclencher des transformations se trouvent l'occurrence de crues, la réalisation d'études (portant sur les aléas, la vulnérabilité, les mesures, etc.), l'échange de connaissances entre les acteurs, ainsi que la recherche de solutions lors de la gestion.¦Les caractéristiques des connaissances varient considérablement selon les acteurs. L'appartenance à un groupe donné ne permet toutefois pas à elle seule de déterminer l'état des connaissances : tous les acteurs peuvent avoir des connaissances pertinentes pour la gestion des risques. Les différences entre les acteurs rendent pourtant la communication compliquée. Ce problème pourrait être atténué par des médiateurs qui assureraient un travail de traduction. Dans la pratique, de telles instances manquent généralement.¦La gestion et les connaissances des risques hydrologiques sont fortement interdépendantes. L'état et les caractéristiques des connaissances déterminent directement la qualité de la protection contre les crues. Des lacunes ou des imprécisions peuvent donc entraîner une gestion non adaptée aux risques présents. Afin d'éviter une telle situation, il est important que les connaissances sur les risques hydrologiques et sur les possibilités d'y faire face soient régulièrement remises à jour. Ne devant pas se restreindre à l'expérience de crues passées, il est impératif qu'elles contiennent aussi des réflexions prospectives et des scénarios novateurs.¦La gestion n'est pas seulement demandeuse en connaissances, elle est également susceptible d'en générer de nouvelles et d'élargir les connaissances existantes. Il convient donc de considérer la création et le transfert de connaissances comme une tâche centrale de la gestion des risques.¦Zusammenfassung Die Rolle der soziopolitischen Parameter und des Wissens im Umgang mit hydrologischen Risiken¦Die Arbeit untersucht drei Themenbereiche: (1) den soziopolitischen Umgang mit hydrologischen Risiken, (2) das Wissen, über das die Akteure bezüglich der Hochwasserrisiken verfügen sowie (3) die Wechselwirkungen zwischen diesen beiden Themenfeldern. Insgesamt wurden drei Fallstudien durchgeführt, darunter zwei regionale Studien (Stadt Bern, Gemeinde Saillon) und eine Untersuchung eines spezifischen Akteurs (Schwellenkorporationen im Kanton Bern). Die empirischen Daten wurden anhand von halbstandardisierten Interviews und schriftlichen Umfragen erhoben.¦Das Management hydrologischer Risiken ist stark von soziopolitischen Parametern beeinflusst, d.h. von Interessen und Zielvorstellungen der Akteure, von Machtverhältnissen und von Verhandlungs- und Entscheidungsprozessen. Die in der Praxis vorgesehenen Schritte zur Reduktion der Hochwasserrisiken beschränken sich jedoch meist auf die physischen, administrativen und technischen Aspekte der Risiken. Die Vernachlässigung ihrer soziopolitischen Dimension führt zu Konflikten, welche die Planung von Hochwasserschutzprojekten deutlich verlangsamen oder gar blockieren. Des Weiteren konzentriert sich das Risikomanagement im Wesentlichen auf die Reduktion der Gefahren. Gesellschaftliche Debatten zur Vulnerabilität sind deutlich seltener, obschon sie für einen umfassenden Umgang mit Risiken unabdingbar sind.¦Angesichts der Bedeutung der soziopolitischen Dimension und der Vulnerabilität ist es notwendig, dass die Vorgehensweise im Risikomanagement überdacht und angepasst wird. Zudem ist eine bessere Integration aller betroffener Akteure unablässig, um mehrheitsfähige Lösungen zu finden. Zur Zeit ist der Rückgriff auf entsprechende Instrumente ungenügend.¦Das Wissen über hydrologische Risiken und deren Management kann in vier Repertoires eingeteilt werden (Systemwissen, Ereigniswissen, Interventionswissen, soziopolitisches Wissen), die alle bei der Reduktion von Risiken bedeutsam sind. Zu den wichtigsten Faktoren, die Wissenstransformationen auslösen, gehören Hochwasserereignisse, die Durchführung von Studien (zu Gefahren, zur Vulnerabilität, zu Massnahmen usw.), der Wissensaustausch zwischen Akteuren und die Suche nach Lösungen während des Risikomanagements.¦Die Merkmale der Wissensformen unterschieden sich stark zwischen den verschiedenen Akteuren. Die Zugehörigkeit eines Akteurs zu einer bestimmten Gruppe ist jedoch kein ausreichendes Kriterium, um dessen Wissensstand zu bestimmen: Alle Akteure können über Wissen verfügen, das für den Umgang mit Risiken relevant ist. Die Unterschiede zwischen den Akteuren gestalten die Kommunikation allerdings schwierig. Das Problem liesse sich entschärfen, indem Mediatoren eingesetzt würden, die als Übersetzer und Vermittler agierten. In der Praxis fehlen solche Instanzen weitgehend.¦Zwischen dem Umgang mit hydrologischen Risken und dem Wissen bestehen enge Wechselwirkungen. Der Zustand und die Eigenschaften der Wissensformen bestimmen direkt die Qualität des Hochwasserschutzes. Lückenhaftes und unpräzises Wissen kann demnach zu einem Risikomanagement führen, das den tatsächlichen Gegebenheiten nicht angepasst ist. Um eine solche Situation zu verhindern, muss das Wissen über Risiken und Hochwasserschutz regelmässig aktualisiert werden. Dabei darf es sich nicht auf die Erfahrung vergangener Hochwasser beschränken, sondern hat auch vorausschauende Überlegungen und neuartige Szenarien einzubeziehen.¦Das Risikomanagement benötigt nicht nur Wissen, es trägt auch dazu bei, neues Wissen zu t generieren und bestehendes zu erweitern. Die Erarbeitung und der Transfer von Wissen sind deshalb als zentrale Aufgaben des Risikomanagements zu betrachten.¦Abstract¦The role of socio-political parameters and of knowledge in the management of hydrological risks¦The purpose of the thesis is to analyse (1) the socio-political management of hydrological risks, (2) the knowledge about hydrological risks, and (3) the interaction between risk management and knowledge. Three case studies were carried out, two at a regional level (city of Berne, village of Saillon) and one about a specific stakeholder (the dyke corporations in the canton of Berne). Empirical data were collected by the means of semi-structured interviews and surveys.¦The management of hydrological risks is highly influenced by socio-political issues, i.e. by interests and goals of stakeholders, by the balance of power between stakeholders, as well as by negotiations and decision-making processes. In practice, however, risk management is mainly constrained by physical, technical, and administrative aspects. The neglect of the socio-political dimension may thus be the source of conflicts which significantly delay the planning and implementation of flood protection measures, or even stop them. Furthermore, risk management mostly concentrates on hazard reduction. Discussions on vulnerability issues are less frequent although they are fundamental for treating risks in a holistic manner.¦Because of the importance of the social-political dimension and of vulnerability issues, it is necessary that the common approach of managing hydrological risks is reconsidered and adapted. Moreover, the integration of all stakeholders that are concerned with hydrological risks is essential for finding solutions which are supported by a majority. For instance, the application of appropriate negotiation instruments is insufficient.¦Knowledge about hydrological risks and their management can be classified into four categories (system knowledge, event knowledge, intervention knowledge, socio-political knowledge) which are all influencing the reduction of risks. Among the most important factors that are likely to trigger knowledge transformations, one can point out flood events, studies about risk parameters (hazards, vulnerability, protection measures, etc.), knowledge exchange between stakeholders, and the search for solutions during risk management.¦The characteristics of knowledge vary considerably between stakeholders. The affiliation to a specific group is thus not a sufficient criterion to determine the quality of a stakeholder's knowledge: every stakeholder may have knowledge that is relevant for risk management. However, differences between stakeholders complicate the communication. This problem could be attenuated by mediators which ensure the translation between stakeholders. In practice, such instances are generally lacking.¦The management and knowledge of hydrological risks are highly interdependent. The state and the characteristics of the four categories of knowledge determine directly the quality of flood protection. Gaps and imprecison may thus lead to forms of management which are not adapted to the actual risks. This kind of situation can be avoided by updating regularly the knowledge about hydrological risks and about protection measures. However, knowledge must not be restricted to the experience of past floods. On the contrary, it is indispensable also to involve prospective reflections and new scenarios.¦Risk management does not only require knowledge, it may also generate new knowledge and enlarge existing knowledge. The creation and the transfer of knowledge has thus to be seen as a central task in risk management.

Kittiwakes strategically reduce investment in replacement clutches.

Many life-history traits are expressed interactively in life, but to a varying extent on different occasions. Changes in trait expression can be accounted for by differences in the quality of the environment ('environmental constraint' hypothesis) or by strategic adjustments, if the relative contribution of the trait to fitness varies with time ('strategic allocation' hypothesis). In birds, egg production is lower in replacement clutches than in first clutches, but it is unknown whether this reduction results from an environmental constraint (e.g. food being less available at the time when the replacement clutch is produced) or from a strategic allocation of resources between the two breeding attempts. To distinguish between these two hypotheses, we performed an experiment with black-legged kittiwakes (Rissa tridactyla). Pairs were either food-supplemented or not before the first clutch was laid onwards and we induced them to produce a replacement clutch by removing eggs once when the first clutch was complete. As predicted by the 'strategic allocation' hypothesis, egg production of food-supplemented and non-food-supplemented birds decreased between first and replacement clutches. This suggests that kittiwakes strategically reduce investment in egg production for their replacement clutches compared to first clutches.

Topics in public finance: social security and taxation

Summary The field of public finance focuses on the spending and taxing activities of governments and their influence on the allocation of resources and distribution of income. This work covers in three parts different topics related to public finance which are currently widely discussed in media and politics. The first two parts deal with issues on social security, which is in general one of the biggest spending shares of governments. The third part looks at the main income source of governments by analyzing the perceived value of tax competition. Part one deals with the current problem of increased early retirement by focusing on Switzerland as a special case. Early retirement is predominantly considered to be the result of incentives set by social security and the tax system. But the Swiss example demonstrates that the incidence of early retirement has dramatically increased even in the absence of institutional changes. We argue that the wealth effect also plays an important role in the retirement decision for middle and high income earners. An actuarially fair, but mandatory funded system with a relatively high replacement rate may thus contribute to a low labor market participation rate of elderly workers. We provide evidence using a unique dataset on individual retirement decisions in Swiss pension funds, allowing us to perfectly control for pension scheme details. Our findings suggest that affordability is a key determinant in the retirement decisions. The higher the accumulated pension capital, the earlier men, and to a smaller extent women, tend to leave the workforce. The fact that early retirement has become much more prevalent in the last 15 years is a further indicator of the importance of a wealth effect, as the maturing of the Swiss mandatory funded pension system over that period has led to an increase in the effective replacement rates for middle and high income earners. Part two covers the theoretical side of social security. Theories analyzing optimal social security benefits provide important qualitative results, by mainly using one general type of an economy. Economies are however very diverse concerning numerous aspects, one of the most important being the wealth level. This can lead to significant quantitative benefit differences that imply differences in replacement rates and levels of labor supply. We focus on several aspects related to this fact. In a within cohort social security model, we introduce disability insurance with an imperfect screening mechanism. We then vary the wealth level of the model economy and analyze how the optimal social security benefit structure or equivalently, the optimal replacement rates, changes depending on the wealth level of the economy, and if the introduction of disability insurance into a social security system is preferable for all economies. Second, the screening mechanism of disability insurance and the threshold level at which people are defined as disabled can differ. For economies with different wealth levels, we determine for different thresholds the screening level that maximizes social welfare. Finally, part three turns to the income of governments, by adding an element to the controversy on tax competition versus tax harmonization.2 Inter-jurisdictional tax competition can generate at least two potential benefits or costs: On a public level, tax competition may result in a lower or higher efficiency in the production of public services. But there is also a more private benefit in the form of an option for individuals to move to a community with a lower tax rate in the future. To explore the value citizens attach to tax competition we analyze a unique popular vote for a complete tax harmonization between communities in the third largest Swiss canton, Vaud. Although a majority of voters would have seemingly benefited from replacing the current tax rate by a revenue-neutral average tax rate, the proposal was rejected by a large margin. Our estimates suggest that the estimated combined perceived benefit from tax competition is in the range of 10%.

Sex chromosomes and male functions: where do new genes go?

The position of a gene in the genome may have important consequences for its function. Therefore, when a new duplicate gene arises, its location may be critical in determining its fate. Our recent work in humans, mouse, and Drosophila provided a test by studying the patterns of duplication in sex chromosome evolution. We revealed a bias in the generation and recruitment of new gene copies involving the X chromosome that has been shaped largely by selection for male germline functions. The gene movement patterns we observed reflect an ongoing process as some of the new genes are very young while others were present before the divergence of humans and mouse. This suggests a continuing redistribution of male-related genes to achieve a more efficient allocation of male functions. This notion should be further tested in organisms employing other sex determination systems or in organisms differing in germline sex chromosome inactivation. It is likely that the selective forces that were detected in these studies are also acting on other types of duplicate genes. As a result, future work elucidating sex chromosome differentiation by other mutational mechanisms will shed light on this important process.

Pain assessment in PICU and NICU: Have we got it right?

Pain assessment in critically ill infants and nonverbal children remains a challenge for health professionals. Despite the numerous pain observational measures that have been developed or adapted for infants and children with impaired communication, pain prevalence in paediatric and neonatal intensive care unit remains too high. As pain assessment has been recognised as a pre-requisite for appropriate pain management, much effort was put in the validation or the adaptation of pain measures with little emphasis on implementation of these instruments into practice. Only a few studies demonstrated the benefit of using standardised protocols for the management of pain to guide practice with variable effects. When standardised protocols are undeniably useful in practice, they do not replace health professionals' clinical reasoning necessary to care for individuals. The diversity of the PICU population makes that pain scores need to be interpreted within its clinical context. This session will present pain assessment as a complex transaction that describes structured clinical reasoning from expert nurses that goes beyond the "silver" standard of hetero-evaluation of pain in non-communicative children. Besides pain scores, several patients and nurses factors play a major role in making decisions about analgesia and/or sedation. Patient's clinical instability, change in patient's clinical status, source for observed agitated behaviour, patient's known reactions to analgesia and sedation and anticipation of risks are factors that should be taken into account when implementing pain assessment and management guidelines in PICU and NICU.

Clutch size and malarial parasites in female great tits.

Life-history models predict an evolutionary trade-off in the allocation of resources to current versus future reproduction. This corresponds, at the physiological level, to a trade-off in the allocation of resources to current reproduction or to the immune system, which will enhance survival and therefore future reproduction. For clutch size, life-history models predict a positive correlation between current measurement in eggs and the subsequent parasite load. Tn a population of great tits, we analyzed the correlation between natural clutch size of females and the subsequent prevalence of Plasmodium spp., a potentially harmful blood parasite. Females that showed, 14 days after hatching of the nestlings, an infection with Plasmodium had a significantly larger clutch (9.3 eggs +/- 0.5 SE, n = 18) than uninfected females (8.0 eggs +/- 0.2 SE, n = 80), as predicted by the allocation trade-off. Clutch size was positively correlated with tile prevalence of Plasmodium, but brood size 14 days after hatching was not. This suggests that females incur higher costs during laying the clutch than during rearing nestlings. Infection status of some females changed between years, and these changes were significantly correlated with a change in clutch size as predicted by die trade-off. The link between reproductive effort and parasitism may represent a possible mechanism by which the cost of egg production is mediated into future survival and may thereby be an important selective force in the shaping of clutch size.

10

Over the last few decades, the Swiss higher education system has faced important reforms - both concerning its structure and its governance. As with other European countries, one of the most important changes consists of the strengthening of the higher education institutions' research mission through the reinforcement of the role of the National Science Foundation (NSF), which has become increasingly involved in sustaining academic careers. Meanwhile, traditionally and historically, the definition of a faculty member and his or her financial support has come from the higher education institutions (HEI) themselves. This redefinition of power relationships around the funding of academic temporary positions and research activities by the NSF can be analyzed as an attempt to reform the structure of academic careers and the allocation modes of academic positions. Being able to analyze the issue of allocating academic positions within the normative structure of science (Merton, The sociology of science. University of Chicago Press, Chicago, 1973) is a constant concern for those involved in Higher Education Studies. This chapter is an attempt to nurture the debate by questioning, though a quantitative and qualitative research, the tension between the uses of universalist and particularist criteria in the allocation of academic positions. It analyses the possible exclusion process as a consequence of the organization of academic markets and their embeddedness in a wider societal organization.

Optimal growth strategies when mortality and production rates are size-dependent

Pontryagin's maximum principle from optimal control theory is used to find the optimal allocation of energy between growth and reproduction when lifespan may be finite and the trade-off between growth and reproduction is linear. Analyses of the optimal allocation problem to date have generally yielded bang-bang solutions, i.e. determinate growth: life-histories in which growth is followed by reproduction, with no intermediate phase of simultaneous reproduction and growth. Here we show that an intermediate strategy (indeterminate growth) can be selected for if the rates of production and mortality either both increase or both decrease with increasing body size, this arises as a singular solution to the problem. Our conclusion is that indeterminate growth is optimal in more cases than was previously realized. The relevance of our results to natural situations is discussed.

Self-selection and risk selection on the Swiss health insurance market

Abstract This thesis presents three empirical studies in the field of health insurance in Switzerland. First we investigate the link between health insurance coverage and health care expenditures. We use claims data for over 60 000 adult individuals covered by a major Swiss Health Insurance Fund, followed for four years; the data show a strong positive correlation between coverage and expenditures. Two methods are developed and estimated in order to separate selection effects (due to individual choice of coverage) and incentive effects ("ex post moral hazard"). The first method uses the comparison between inpatient and outpatient expenditures to identify both effects and we conclude that both selection and incentive effects are significantly present in our data. The second method is based on a structural model of joint demand of health care and health insurance and makes the most of the change in the marginal cost of health care to identify selection and incentive effects. We conclude that the correlation between insurance coverage and health care expenditures may be decomposed into the two effects: 75% may be attributed to selection, and 25 % to incentive effects. Moreover, we estimate that a decrease in the coinsurance rate from 100% to 10% increases the marginal demand for health care by about 90% and from 100% to 0% by about 150%. Secondly, having shown that selection and incentive effects exist in the Swiss health insurance market, we present the consequence of this result in the context of risk adjustment. We show that if individuals choose their insurance coverage in function of their health status (selection effect), the optimal compensations should be function of the se- lection and incentive effects. Therefore, a risk adjustment mechanism which ignores these effects, as it is the case presently in Switzerland, will miss his main goal to eliminate incentives for sickness funds to select risks. Using a simplified model, we show that the optimal compensations have to take into account the distribution of risks through the insurance plans in case of self-selection in order to avoid incentives to select risks.Then, we apply our propositions to Swiss data and propose a simple econometric procedure to control for self-selection in the estimation of the risk adjustment formula in order to compute the optimal compensations.

Local Public-Services Provision under Public-Private Partnerships : Contractual Design and Contracting Parties Incentives

When deciding to resort to a PPP contract for the provision of a local public service, local governments have to consider the demand risk allocation between the contracting parties. In this article, I investigate the effects of demand risk allocation on the accountability of procuring authorities regarding consumers changing demand, as well as on the cost-reducing effort incentives of the private public-service provider. I show that contracts in which the private provider bears demand risk motivate more the public authority from responding to customer needs. This is due to the fact that consumers are empowered when the private provider bears demand risk, that is, they have the possibility to oust the private provider in case of non-satisfaction with the service provision, which provides procuring authorities with more credibility in side-trading and then more incentives to be responsive. As a consequence, I show that there is a lower matching with consumers' preferences over time when demand risk is on the public authority rather than on the private provider, and this is corroborated in the light of two famous case studies. However, contracts in which the private provider does not bear demand risk motivate more the private provider from investing in cost-reducing efforts. I highlight then a tradeoff in the allocation of demand risk between productive and allocative efficiency. The striking policy implication of this article for local governments would be that the current trend towards a greater resort to contracts where private providers bear little or no demand risk may not be optimal. Local governments should impose demand risk on private providers within PPP contracts when they expect that consumers' preferences over the service provision will change over time.

Le couple à l'épreuve du désengagement sportif : accompagnements, arrangements et tensions

At the end of a sporting career, triathletes are often living as a couple and the cessation of sport has an effect on the their relationship. While a large part of the existence and identity of the couple is dedicated to the triathlon, disengagement from sport undeniably changes the gender balance. The allocation of roles is not a linear process in a couple, and the effects of giving up sport have not really been studied. Therefore, this article focuses on how couples deal with the various ways a sporting career comes to an end, which are characterized by changes in direction and temporary or permanent cessation. Sex, roles, age, social class, respective commitments or the fact of having children are variables taken into account in this analysis. The survey is based on interviews conducted with 10 couples. The analysis suggests that the disengagement from sport depends on how compromise was established during the sporting career. Between those who support their partner's sporting career, those who share it intermittently and those who pursue their own activities even to the exclusion of the other, the way to manage disengagement can vary depending on the situation and the roles assigned to each person.

Essays in equilibrium asset pricing

Introduction This dissertation consists of three essays in equilibrium asset pricing. The first chapter studies the asset pricing implications of a general equilibrium model in which real investment is reversible at a cost. Firms face higher costs in contracting than in expanding their capital stock and decide to invest when their productive capital is scarce relative to the overall capital of the economy. Positive shocks to the capital of the firm increase the size of the firm and reduce the value of growth options. As a result, the firm is burdened with more unproductive capital and its value lowers with respect to the accumulated capital. The optimal consumption policy alters the optimal allocation of resources and affects firm's value, generating mean-reverting dynamics for the M/B ratios. The model (1) captures convergence of price-to-book ratios -negative for growth stocks and positive for value stocks - (firm migration), (2) generates deviations from the classic CAPM in line with the cross-sectional variation in expected stock returns and (3) generates a non-monotone relationship between Tobin's q and conditional volatility consistent with the empirical evidence. The second chapter proposes a standard portfolio-choice problem with transaction costs and mean reversion in expected returns. In the presence of transactions costs, no matter how small, arbitrage activity does not necessarily render equal all riskless rates of return. When two such rates follow stochastic processes, it is not optimal immediately to arbitrage out any discrepancy that arises between them. The reason is that immediate arbitrage would induce a definite expenditure of transactions costs whereas, without arbitrage intervention, there exists some, perhaps sufficient, probability that these two interest rates will come back together without any costs having been incurred. Hence, one can surmise that at equilibrium the financial market will permit the coexistence of two riskless rates that are not equal to each other. For analogous reasons, randomly fluctuating expected rates of return on risky assets will be allowed to differ even after correction for risk, leading to important violations of the Capital Asset Pricing Model. The combination of randomness in expected rates of return and proportional transactions costs is a serious blow to existing frictionless pricing models. Finally, in the last chapter I propose a two-countries two-goods general equilibrium economy with uncertainty about the fundamentals' growth rates to study the joint behavior of equity volatilities and correlation at the business cycle frequency. I assume that dividend growth rates jump from one state to other, while countries' switches are possibly correlated. The model is solved in closed-form and the analytical expressions for stock prices are reported. When calibrated to the empirical data of United States and United Kingdom, the results show that, given the existing degree of synchronization across these business cycles, the model captures quite well the historical patterns of stock return volatilities. Moreover, I can explain the time behavior of the correlation, but exclusively under the assumption of a global business cycle.