This dissertation consists of three essays. The first essay studies how health risk affects individuals' economic decisions due to changes in productivity, required medical expenditures, available time and survival probabilities implied by changes in health status. It assesses the role of these four channels in determining labour supply, asset accumulation and welfare using a life-cycle model calibrated to the U.S. economy. I find that all channels and the interactions between them have large implications for the macroeconomic variables studied. Health has larger effects for the non-college than college educated, explaining a significant fraction of the difference in labour supply, degree of reliance on government transfers and asset accumulation across education groups. Improving non-college health outcomes to approach those of college graduates results in large welfare gains, higher labour supply, and significantly lower reliance on government welfare programs. The second essay studies the evolution of wage inequality in the United States between 1980 and 2002 in a framework that accounts for changes in the employment of physical and cognitive skills and their returns. I find that within education-gender groups, average employed cognitive skills have remained constant, while average physical skills have declined. The returns to high levels of cognitive skills have increased dramatically, while returns to low levels of cognitive skills and physical skills have remained approximately constant. Skills account for approximately half of the increase in the college wage premium, and for a small but growing fraction of residual wage inequality. The final essay studies the sorting decisions of students with different levels of analytical and verbal skills into college fields of study. I build a model where each field tests and perfectly reveals to potential future employers only the students' skill that is intensively required in that field. Students' expected wages after graduation are a function of their revealed skill levels and firms' expectations of the unrevealed skills given the chosen field. I show how the size of each field and the average talent it attracts depend on the average skill levels, on skill dispersion and on the degree of correlation between skills in the student population.

Med anledning av bristande forskning om sponsorrelationers utveckling, är studiens syfte att öka förståelsen för vilka relationskomponenter som är avgörande för sponsorrelationens olika livscykelfaser. Studien syftar specifikt till att undersöka evenemangssponsring. För att uppnå studiens syfte genomfördes två fallstudier om en pågående sponsorrelation mellan Arla och Tjejmilen, samt en avslutad sponsorrelation mellan Arla och Vasaloppet. En representant från respektive organisation intervjuades. Materialet analyserades utifrån det teoretiska ramverket, vilket utgjordes av en livscykelmodell. Formationsfasens avgörande komponent var relationsspecifika investeringar, den möjliggjorde utveckling av tillit. Operationaliseringsfasen karaktäriserades av kunskapsdelning samt kompletterande resurser, eftersom parterna upprätthöll sina ansträngningar utvecklades relationerna till resultatfasen. De hängivna kontaktpersonerna var en viktig faktor för funktionen av samtliga relationskomponenter och att sponsorrelationen kunde utvecklas. Till skillnad från tidigare forskning tyder resultaten på att sponsorrelationens parter var övertygade om att resurserna och kunskaperna var kompatibla redan innan formationsfasen hade inletts. Därmed identifierades en begynnelsefas som inträffar innan sponsorrelationens formationsfas. / Owing to insufficient research on the development of sponsorship, the purpose of the study is to increase the understanding of which relational components are crucial in the different life cycle stages of sponsorship relationships. The study investigates event sponsorship. Two case studies were conducted: an ongoing sponsorship relationship between Arla and Tjejmilen and a finished between Arla and Vasaloppet. Interviews were held with the representatives. The analysis was based on a life cycle model. Specific relational investments were crucial in the formation stage. The operationalization stage was characterized by knowledge-sharing and complementary resources. As parties sustained their efforts, relations developed into the outcome stage. The devoted contact persons were important for the function of all relationship components. The parties of the sponsorship relationship were convinced that their resources and knowledges were compatible before the formation stage. Thus, an initial stage was identified, which occurs before the formation stage.

Using 2002-2006 Household Budget Survey, this thesis investigates the income, consumption and saving dynamics of Turkish households within a life-cycle theory framework by employing cross-sectional analyses and cohort techniques. Cohort techniques are used not only to analyze these variables, but also to investigate the demographics and components of income and consumption. The analyses are deepened by dividing the sample according to the location of the households (urban-rural areas), and significant differences are found between urban and rural households, especially in terms of saving behaviors. Income, consumption and savings of formal and informal households are also investigated. Analyzing these households provides information regarding the precautionary saving since the higher income uncertainty of the informal households is expected to force them for extra saving due to precautionary motive. Finally, the life-cycle model and the precautionary saving hypothesis are tested by estimating log-linearized Euler equations. In the test of precautionary saving hypothesis, formal-informal data are used as a proxy for the risk variable. According to the estimation results, the predictions of the life-cycle model do not hold for Turkey but there is no evidence that this is due to precautionary saving.

Dans cette thèse, j’examine l’effet de l’incertitude sur les comportements de consommation dans les modèles de cycle de vie. Bien qu’on ait fait le constat depuis les années 1980 que l’incertitude peut modifier de manière substantielle les prédictions des modèles de cycle de vie, certains des mécanismes en jeu sont encore mal connus. Dans le chapitre 1, j’étudie les conséquences de la présence d’incertitude sur la croissance de la consommation, et je montre qu’elles mettent en cause la croyance existante selon laquelle la consommation obéirait une marche aléatoire dans les modèles de cycle de vie standards. En effet, l’incertitude pousse les ménages prudents (c'est-à-dire qui ont une utilité marginale convexe) à réallouer une partie de leur consommation présente vers le future, qui est incertain, et donc à choisir un niveau de consommation présent inférieur à leur niveau de consommation future espérée. Cela implique que des variables autres que la consommation présente améliorent la prédiction de la consommation future, car elles permettent de prédire la différence de précaution entre consommation présente et consommation future. Dans le chapitre 2, je considère l’impact de l’incertitude sur le niveau de consommation des ménages, comment il varie selon leur revenu et leur richesse, et donc comment leur consommation répond à des chocs de revenus. Puisque la présence d’incertitude induit les ménages à allouer une part plus grande de leurs ressources aux périodes futures, ils épargnent davantage à la période présente. Je mets en évidence le fait que cette épargne supplémentaire, baptisée épargne de précaution, varie de manière décroissante et concave avec la part transitoire du revenu et avec la richesse, mais de manière croissante et convexe avec la part permanent du revenu. Dans le chapitre 3, je tire les conséquences de ces résultats pour la mesure empirique de la réponse de la consommation à des chocs de revenu. Je m’appuie sur les résultats des chapitres 1 et 2 pour montrer que, dans les modèles de cycle de vie standards, la croissance de la consommation est négativement corrélée aux réalisations des chocs transitoires passés, à cause du comportement de précaution. Une telle corrélation induirait un biais dans une méthode fréquemment utilisée pour estimer la réponse de la consommation à des chocs de revenu transitoires, développée par Blundell, Pistaferri and Preston (2008). En effet, leur méthode attribuerait aux chocs transitoires présents les variations de la consommation expliquées par les chocs passés, prédisant ainsi une réponse trop faible aux chocs transitoires. Je généralise cette méthode pour prendre en compte l’influence possible des chocs passés sur la croissance de la consommation. Avec cet estimateur plus flexible, j’obtiens que la réponse de la consommation à des chocs transitoires est statistiquement significative et que sa magnitude concorde avec les études sur la réponse de la consommation à des baisses d’impôts transitoires. / In this dissertation, I examine the impact of uncertainty on consumption decisions, known as precautionary saving, a life-cycle model.In the first chapter, I generalize and correct previous findings comparing consumption and its response to variations in assets and permanent income in the presence and in the absence of uncertainty. I establish that, in a multiperiod life-cycle model, under some conditions on the marginal utility function that are verified by standard preferences, the presence of uncertainty increases saving. The variations in this additional saving makes consumption more responsive to variations in assets, concave in assets, less responsive to variations in permanent income, and concave in permanent income.In the second chapter, I draw the implications of these results for existing expressions of consumption. Precautionary saving implies a departure from random walk representations of consumption. It remains inadequate when considering approximation of the life-cycle model around small income shocks or small variance parameters.In the third chapter, I build on these results to explain the discrepancies between two methods used for the estimation of the consumption response to transitory income shocks. Indeed, the presence of precautionary behavior induces a correlation between consumption growth and the realization of past shocks. Some of the existing estimation methods neglect this correlation, so that, in the presence of precautionary behavior, the variations caused by past shocks are attributed to consumption's response current transitory shocks, causing an estimation bias. A number of other mechanisms can induce a correlation with past shocks, such as liquidity constraints or habit persistence, generating a similar bias. I develop a generalized version of these estimators that takes into account the possibility of a correlation between consumption growth and past shocks. The results that I obtain is consistent with the findings derived from other methods.

Over the last two decades, implementation of membrane bioreactors (MBRs) has increased due to their superior effluent quality and low plant footprint. However, they are still viewed as a high-cost option, both with regards to capital and operating expenditure (capex and opex). The present thesis extends the understanding of the impact of design and operational parameters of membrane bioreactors on energy demand, and ultimately whole life cost. A simple heuristic aeration model based on a general algorithm for flux vs. aeration shows the benefits of adjusting the membrane aeration intensity to the hydraulic load. It is experimentally demonstrated that a lower aeration demand is required for sustainable operation when comparing 10:30 to continuous aeration, with associated energy savings of up to 75%, without being penalised in terms of the fouling rate. The applicability of activated sludge modelling (ASM) to MBRs is verified on a community-scale MBR, resulting in accurate predictions of the dynamic nutrient profile. Lastly, a methodology is proposed to optimise the energy consumption by linking the biological model with empirical correlations for energy demand, taking into account of the impact of high MLSS concentrations on oxygen transfer. The determining factors for costing of MBRs differ significantly depending on the size of the plant. Operational cost reduction in small MBRs relies on process robustness with minimal manual intervention to suppress labour costs, while energy consumption, mainly for aeration, is the major contributor to opex for a large MBR. A cost sensitivity analysis shows that other main factors influencing the cost of a large MBR, both in terms of capex and opex, are membrane costs and replacement interval, future trends in energy prices, sustainable flux, and the average plant utilisation which depends on the amount of contingency built in to cope with changes in the feed flow.

The focus of the dissertation is on software quality assurance for object-oriented information systems development. A Quality Assurance Reference Model is proposed with aspects dealing with technical and managerial issues. A revised Spiral life cycle model is adopted as well as the Object Modelling Technique. The Quality Assurance Reference Model associates quality factors at various levels, quality criteria and metrics into a matrix framework that may be used to achieve quality assurance for all cycles of the Spiral Model. / Computing / M. Sc. (Information Systems)

We study skill- and income-related differences in the access to health care as drivers of longevity inequality from a theoretical life-cycle as well as from a macroeconomic perspective. To do so, we develop an overlapping generations model populated by heterogeneous agents subject to endogenous mortality. We model two groups of individuals for whom differences in skills translate into differences in income and in the ability to use medical technology effectively in curbing mortality. We derive the skill- and age-specific individual demand for health care based on the value of life, the level of medical technology and the market prices. Calibrating the model to the development of the US economy and the longevity gap between the skilled and unskilled, we study the impact of rising effectiveness of medical care in improving individual health and examine how disparities in health care utilisation and mortality emerge as a consequence. In so doing, we explore the role of skill-biased earnings growth, skill-bias in the ability to access state-of-the art health care and to use it effectively, and skill-related differences in health insurance coverage. We pay attention to the macroeconomic feedback, especially to medical price inflation. Our findings indicate that skill-bias related to the effectiveness of health care explains a large part of the increase in the longevity with earnings-related differences in the utilisation of health care taking second place. Both channels tend to be reinforced by medical progress.

Detta forskningsarbete lyfter den problematik somdebatterats kring proveniensprincipen och den ombildningdenna princip har mött sedan digitaliserings ankomst.Studiens avsikt var att påvisa vilken innebörd principen haridag i en modern informationsförvaltning och deninformationshantering som sker där. Syftet var även attundersöka hur informationsförvaltningen arbetar proaktivtmed att garantera proveniens i all sin informationshantering,samt belysa hur proveniens förstås i förhållande till valet avmetod kring informationshanteringen.Undersökningen var kvalitativ och utfördes på tiokommunarkiv i form av att varje kommuns kommunarkivariedjupintervjuades. I undersökningen har även planer kringinformationshantering en studerats. Studien konstaterar vilkaförenklingar som digitaliseringen inneburit kring att säkerställa proveniens, där automatiserad och utvecklad metadataskapat verklig proveniens som kan påvisa informationenssamband med den process och det sammanhang där den harbefunnit sig. Uppsatsen diskuterar även de bekymmer somuppstår då digitaliserad information ordnas på helt andra sättän tidigare och vilka konsekvenser detta får för hur vi skaförhålla oss till och förstå proveniens.Resultatet visar att informationsförvaltningarna kan borga föryttre proveniens vad gäller arkivmaterialet men inte helahandlingsbeståndet. Studien fastslår vidare att inreproveniens som en spegling av organisationens verksamhetmåste förstås utifrån hela handlingsbeståndet och desslogiska ordning, snarare än utifrån arkivmaterialets synliga.Undersökningen konstaterar även betydelsen av proaktivitetkring arbetet med att tydliggöra informationens processuellakontext, samt tidig metadataapplicering ochsystemutveckling som behåller metadata genom allaprocesser. Uppsatsen understryker slutligen att detta inte görsi den utsträckning som är nödvändig. / This essay describes the debate about the principle ofprovenance and its multiple forms, and the transformationsof these forms, due to the coming of electronic informations.The thesis intended to explain the definitions of the principlein a modern information management and there explore howthey operate proactively to assure provenance.The qualitative investigation was carried out at tenmunicipality final archives, where each municipalityarchivist was being interviewed. The study expounds in whatway the digitisation has simplified the methods to conductassured provenance, where automated metadata shows therelationships of the information to function and process. Theessay also debates the difficulties that appear when digitalinformation are being organized in different ways thananalogue information, and how this fact requires a newinterpretation of the principle of provenance.The researcher concludes that the investigated archives,ensure respect des fonds when it concerns the content of thearchives, but not when it comes to the whole content of theinformation management. The result of the study also showsthat the respect of original order as a reflection of theorganization, has to be understood throughout all content ofthe management and its logical order, rather than the visiblecontent that the archives embrace. Furthermore the thesisobserves the importance of proactivity, regarding theclarification of the relationships between the information andthe processes that produce and use them. This could beachieved with early application of metadata and developmentof systems that keep metadata trough all processes. Theconclusion of the essay is that this is not pursued in theextension that is required.

The focus of the dissertation is on software quality assurance for object-oriented information systems development. A Quality Assurance Reference Model is proposed with aspects dealing with technical and managerial issues. A revised Spiral life cycle model is adopted as well as the Object Modelling Technique. The Quality Assurance Reference Model associates quality factors at various levels, quality criteria and metrics into a matrix framework that may be used to achieve quality assurance for all cycles of the Spiral Model. / Computing / M. Sc. (Information Systems)

Au cours de cette thèse, nous avons examinée les pratiques actuelles en matière d'éducation en IS. Nous avons proposé une approche centrée sur l'utilisation des processus normalisés en IS, tout en faisant en sorte que le scénario d'apprentissage soit très adaptable et qu'il puisse être piloté par les compétences d'IS acquises ou à acquérir. Ensuite, une plateforme Web a été développée pour soutenir cette nouvelle approche d'apprentissage. En utilisant cette approche, les étudiants ne seront pas seulement en mesure de bien concevoir le système demandé de manière distante et collaborative, mais ils seront aussi capables de l'élaborer de manière appropriée. Cela leur permettra d'apprendre les principes et processus fondamentaux de l'IS, à mieux communiquer dans un environement de travail, la gestion d'équipe, la collaboration et les compétences techniques connexes. Les formateurs d'un autre côté pourront mieux gérer leur parcours d'apprentissage, les ressources pédagogiques, et les résultats escomptés. En utilisant cette solution, les organisations de ces formateurs et étudiants, c'est-à-dire les universités et collèges, pourront gérer et normaliser les compétences acquises par leurs futurs ingénieurs systèmes à tous les niveaux. / This thesis surveys the current practices and advancements in SE education. We ended up proposing a novel solution for SE education (an approach with its supporting web-based platform). The proposed approach is based on the recommendations of academic and industrial communities. It is centered around the use of SE standardized processes and at the same time very adaptive, with learning scenarios that can be driven by the acquired or to-be-taught SE competencies. The proposed solution is a web based platform that has been developed to support this novel approach within a distant Project Based Learning (PBL) environment. The solution aims to ease the learning at the same time of fundamental principles and processes of systems engineering, along with communication, team management, collaboration, and related soft skills. On the other hand, educators will be able to better manage their learning scenarios, training resources, and the expected outcomes. Last, educators and students' organizations using this solution will be able to manage and normalize the competencies to be acquired by their future systems engineers at every level.