Institut für Health Care & Public Management

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Qualitatives, räumliches Schließen zur Kollisionserkennung und Kollisionsvermeidung autonomer BDI-Agenten
(2011) Kirn, Stefan; Schüle, Michael
Die Trends und Veränderungen in der Logistik führen zu einem dezentralen Ansatz der Steuerungssysteme, um die Komplexität logistischer Systeme zu reduzieren. Softwareagenten, insbesondere BDI-Agenten (Belief-Desire-Intention), als Gegenstand dieser Arbeit, bieten aufgrund ihrer Eigenschaften geeignete Konzepte diesen Ansatz umzusetzen. Im räumlichen Kontext ist das Wissen der Agenten über ihre Umwelt häufig unsicher. Dieser Beitrag adressiert das Problem der autonomen, kollisionsfreien Bewegung von mehreren, interagierenden Agenten auf Basis von unsicherem Wissen im Kontext der Transportlogistik. Zu diesem Zweck bietet die Perspektive des qualitativ räumlichen Schließens geeignete Konzepte. Der Ansatz wird durch eine Multiagentensimulation in einem transportlogistischen Szenario, im Speziellen mit verschiedenen organisationstheoretischen Konzepten bezüglich des Verhaltens der Agenten ausgewertet.
Work time and hours constraints
(2012) Otterbach, Steffen; Sousa-Poza, Alfonso
This thesis aims to draw a comprehensive picture of labor supply hours and the extent and determinants of work hours constraints while pinpointing possible consequences and policy implications of such constraints and highlighting the relevance of individual work time preferences with respect to a meaningful debate on work time issues. Most particularly, it offers a comprehensive analysis of how the consideration of individually preferred work hours and the discrepancy between these and actual work hours can foster an understanding of individual labor market participation decisions. What insights, for example, do individual preferences for work hours provide for successful policy implementation if policy makers address topics such as the length of the work week, balance between work and family life or the need for more substantive part-time jobs? Likewise, what incentives might lead employers to reduce work hour mismatches? Despite their importance, these issues of work hour preferences and constraints have not yet been adequately considered in the overall debate on work time and labor market policy. Nor has attention been paid to a further pivotal question: how these restrictions affect workers´ health and well-being. To date, there are only a few studies that investigate the meaning of work hours constraints in the context of happiness and well-being in the work place. This thesis, therefore, constitutes the first study for Germany and the United Kingdom on the potential adverse health consequences of being constrained in the choice of number of work hours.
Risiken aus Cloud-Computing-Services : Fragen des Risikomanagements und Aspekte der Versicherbarkeit
(2013) Haas, Andreas; Hofmann, Annette
Cloud-Computing services are changing the risk situation of IT-outsourcing and represent a challenge for the insurance industry. The most important problem to guarantee insurability of these emerging risks is that they are not stochastically independent. On the one hand, the interdependent network structure of these risks implies a significant contagion risk; on the other hand, new risks emerge that have not been addressed by existing (cyber risk) policies so far. Insurance concepts should be supported by innovative risk diversification concepts for cloud computing service. Addressing and classifying the new risks resulting from Cloud-Computing services, this article discusses insurability issues and risk management solutions.
How does subjective well-being evolve with age? A literature review
(2013) Sousa-Poza, Alfonso; Moeller, Valerie; López Ulloa, Beatriz Fabiola
This literature review provides an overview of the theoretical and empirical research in several disciplines on the relation between ageing and subjective well-being, i.e., how subjective well-being evolves across the lifespan. Because of the different methodologies, data sets and samples used, comparison among disciplines and studies is difficult. However, extant studies do show either a U-shaped, inverted U-shaped or linear relation between ageing and subjective well-being.
Ageing and productivity
(2013) Bloom, David E.; Sousa-Poza, Alfonso
Job insecurity, employability, and health : an analysis for germany across generations
(2014) Otterbach, Steffen; Sousa-Poza, Alfonso
In this paper, we use 12 waves of the German Socio-Economic Panel to examine the relationship between job insecurity, employability and health-related well-being. Our results indicate that being unemployed has a strong negative effect on life satisfaction and health. They also, however, highlight the fact that this effect is most prominent among individuals over the age of 40. A second observation is that job insecurity is also associated with lower levels of life satisfaction and health, and this association is quite strong. This negative effect of job insecurity is, in many cases, exacerbated by poor employability.
Multiagent resource allocation in service networks
(2014) Karänke, Paul; Kirn, Stefan
The term service network (SN) denotes a network of software services in which complex software applications are provided to customers by aggregating multiple elementary services. These networks are based on the service-oriented computing (SOC) paradigm, which defines the fundamental technical concepts for software services over electronic networks, e.g., Web services and, most recently, Cloud services. For the provision of software services to customers, software service providers (SPs) have to allocate their scarce computational resources (i.e., hardware and software) of a certain quality to customer requests. The SOC paradigm facilitates interoperability over organizational boundaries by representing business relationships on the software system level. Composite software services aggregate multiple software services into software applications. This aggregation is denoted as service composition. The loose coupling of services leads to SNs as dynamic entities with changing interdependencies between services. For composite software services, these dependencies exist across SN tiers; they result from the procurement of services, which are themselves utilized to produce additional services, and constitute a major problem for resource allocation in SNs. If these dependencies are not considered, the fulfillment of agreements may become unaccomplishable (overcommitment). Hence, the consideration of service dependencies is crucial for the allocation of service providers resources to fulfill customer requests in SNs. However, existing resource allocation methods, which could consider these dependencies -- such as combinatorial auctions with a central auctioneer for the whole SN -- are not applicable, since there are no central coordinating entities in SNs. The application of an allocation mechanism that does not consider these dependencies might negatively affect the actual service delivery; results are penalty payments as well as a damage to the reputation of the providers. This research is conducted in accordance to the design science paradigm in information system research. It is a problem-solving paradigm, which targets the construction and evaluation of IT artifacts. The objectives of this research are to develop and evaluate an allocation protocol, which can consider multi-tier service dependencies without the existence of central coordinating entities. Therefore, an interaction protocol engineering (IPE) perspective is applied to solve the problem of multi-tier dependencies in resource allocation. This approach provides a procedure model for designing interaction protocols for multiagent systems, and is closely related to the well-established area of communication protocol engineering. Automated resource allocation in SNs is analyzed in this research by representing the actors as autonomous software agents in the software system. The actors delegate their objectives to their software agents, which conduct the negotiations for service provision on their behalf. Thus, these agents communicate concerning the resource allocation; in this process, the sequence of communication interactions is crucial to the problem addressed. Interaction protocols define a structured exchange of defined messages between agents; they facilitate agent conversations. When multiple agents have to reach agreements by negotiation and bargaining, such as in case with allocating scarce resources, game theory provides means to formalize and analyze the most rational choice of actions for the interacting agents. Based on a formal framework for resource allocation in SNs, this research first performs a game-theoretic problem analysis; it is concerned with the existence, as well as the complexity of computing optimal allocations. In addition, Nash equilibria are analyzed for optimal allocations. Second, a distributed, auction-based allocation protocol, which prevents overcommitments and guarantees socially optimal allocations for single customer requests under certain assumptions, is proposed. Therefore, a game-theoretic model and an operationizable specification of the protocol are presented. Third, it is formally verified that the protocol enables multi-tier resource allocation and avoids overcommitments by proofs for the game-theoretic model and by model checking for the interaction protocol specification; using the model checker Spin, safety properties like the absence of deadlock are as well formally verified as the protocol enabling multi-tier resource allocation. Fourth, the efficacy and the benefits of the proposed protocol are demonstrated by multiagent simulation for concurrent customers. The experimental evaluation provides evidence of the protocols efficiency compared to the socially optimal allocation as a centralized benchmark in different settings, e.g., network topologies and different bidding policies.
Flexibilisierung synchronisationsdefekter Beschaffungsketten : Entwurf eines fachkonzeptuellen Datenmodells für Logistik-Anwendungssysteme am Beispiel mechatronischer Produkte in der Automobilwirtschaft
(2014) Weiss, Daniel; Kirn, Stefan
The thesis investigates supply chains of mechatronic products in the automotive industry. In the past supply chains often were considered as stable, intercompany relations with long-running general agreements, predefined services and service flows. Due to the differentiation of demand in the form of complex mechatronic products, those stable relations, nowadays, are increasingly fading. From a customer’s point of view “mechatronic supply chains” result in increasing information acquisition costs, as procurement decision alternatives along mechatronic supply chains are often defective (e.g. inadequately assessable). This loss of control during the procurement process occurs due to the fact that mechatronic products as well as their components and parts show a high level of variety, different technologies and divergent life cycle stages. With regard to an entire mechatronic supply chain, the thesis describes this observation as a synchronization defect. Since the specific attributes of mechatronic supply chains do not allow the use of standard synchronization methods, the thesis aims to flexibilize the supply chain by means of IT application systems. Therefore, in particular, the thesis designs a conceptual data model which reduces information acquisition costs during the procurement initiation and processing along mechatronic supply chains, opening up shorter reaction times and/or additional options for action. Conceptual data models describe business problems from an IT application systems’ point of view. The design of a new data model is required due to the fact that the investigated conceptual data models showed only a small benefit related to the problem. The investigated models often were too unspecific and/or designed for other purposes (e.g. other tasks, industries).
The economics of elderly care
(2015) Bauer, Jan Michael; Sousa-Poza, Alfonso
Longer life expectancy and low fertility rates increase the share of elderly among the population of most industrialized countries. This demographic change affects the economy and the society and is most likely to proceed in the future. Therefore, policy makers and families need to be aware of the implications associated with an aging population. One particularly great challenge comes with the rising number of fragile elderly people, for which most countries are currently unable to provide sufficient care solutions. Germany, for instance, is facing a constantly rising share of people in need that mostly receive informal care from friends and family. Public support promotes these informal care arrangements (§3 SGB XI) and endorses care receivers to remain in their domestic environment. Even though such informal care arrangements are preferred by most families, caregiving can have a large impact on the caregiver’s life. Policy makers need to measure and incorporate these outcomes in order to provide suitable aid for caring families and, thereby, ensuring sustainable and dignified population aging. This dissertation consists of three academic papers and contributes to the topic in several ways: the first paper reviews the recent literature on the effects of informal caregiving on the caregiver and, thereby, assesses the opportunity costs associated with informal care provision. Further, we evaluated the methodology that is commonly used and identify certain risk groups as well as arrangements that are particularly burdensome. The second paper takes a specific look at the subjective well-being of caregivers in Germany and analyzes effects associated with providing care. In contrast to most prior studies, the paper uses large population-based longitudinal data, accounts for unobserved heterogeneity, and estimates the relationship with different methodologies. The paper further values well-being losses monetarily, which allows a comparison to formal care alternatives. The third paper provides new insights on individual selection behavior in the market for supplemental health insurances. This is an increasingly popular way to insure against long-term care needs, a risk not fully covered despite a statutory long-term care insurance. Private insurance markets are fragile in the presences of asymmetric information and, therefore, might not be a sustainable solution to cover the increasing risks of an aging society. We developed an innovative approach to disentangle different selection behaviors in a heterogeneous sample and identify asymmetric information exemplarily for the market of supplemental dental insurance, despite no risk-coverage correlation for the aggregated sample.
Der Zusammenhang zwischen Preis und Qualität auf Konsumgütermärkten : Befunde, Interpretationen, Schlussfolgerungen
(2015) Imkamp, Heiner; Sousa-Poza, Alfonso
For more than 60 years, numerous studies have shown low price-quality correlations on consumer goods markets. The coefficients are mostly close to 0.2. That prices fail to function as valid indicators of product quality has often been interpreted as informational market failure. This dissertation, however, argues, that, according to the economic theory of price formation, prices are not an indicator of quality, but an indicator of scarcity. This allows the conclusion that workable consumer goods markets, at least as seen from the consumers point of view, should be characterized by low or even negative correlation coefficients rather than by strong positive coefficients.
Commute time and subjective well-being in urban China
(2015) Sousa-Poza, Alfonso; Nie, Peng
Using data from the 2010 China Family Panel Studies, this study investigates the association between commute time and subjective well-being in a sample of 16- to 65-year-old employees in urban China. We find evidence that a longer commute time is associated with lower levels of both life satisfaction and happiness, especially when the commute times are extreme (≥ 1 hour per day). A multiple mediation analysis further indicates that the relation between commute time and happiness is partially mediated by time spent on daily activities, particularly sleeping. We calculate the amount of income necessary to compensate an employee’s loss in well-being at approximately 82 yuan per hour of commute time, implying that, in urban China, the annual loss of well-being amounts to around 10 billion yuan.
Internet use and subjective well-being in China
(2015) Sousa-Poza, Alfonso; Nimrod, Galit; Nie, Peng
Using data from the 2010 China Family Panel Studies, we analyze the association between Internet use and various measures of subjective well-being (SWB) in a sample of 16- to 60- year-old Chinese. Our analysis shows that although intensive Internet use is significantly associated with lower levels of SWB, we hardly observe any associations when the focus is on participation in specific online activities. Nevertheless, SWB depends on perceptions of Internet use; that is, the importance that different individuals ascribe to different purposes for using the Internet and how much they believe that their Internet use is displacing other activities. Our results suggest that, contrary to previous findings, differences in beneficial outcomes (the third level digital divide) do not necessarily arise from individuals’ actual Internet use (the second level digital divide) but rather may result from their subjective perceptions of such usage. Our findings also point to a possible cultural factor that puts Chinese Internet users at psychological risk.
Essays on health and nutrition in China
(2015) Nie, Peng; Sousa-Poza, Alfonso
This dissertation aims to investigate several major socio-economic determinants of health and nutrition in China. By using data from the China Health and Nutrition Survey (CHNS) spanning from 1991 to 2009, this enhances the understanding of the transition of health and nutrition with such unprecedented economic and social changes in China. This dissertation contains six chapters: more specifically, Chapter 1 gives a brief description of general background, research aim and also the outline. Then Chapter 2 examines the association between maternal employment and childhood obesity. Chapter 3 takes a comprehensive look at how income changes are related to calorie intake. Chapter 4 investigates the impacts of peers (one of most important aspects of social networks) on childhood and adolescent adiposity. Chapter 5 assesses the nexus between long work hours and health. Finally, Chapter 6 ends with some main conclusions and discussions. Chapter 2 analyses the alarming increase of overweight and obese children and considers the higher female employment participation in China. We analyze how maternal employment is correlated with childhood obesity in China. Our work makes a non-Western comparison in this field, which is useful as it is rather difficult to generalize the results (mostly significant positive association between maternal employment and childhood obesity) from related studies in the Western world. More importantly, we further explore how maternal employment is related to two key transmitters of obesity: diet and physical activities. We find no association of maternal employment and childhood adiposity. Moreover, maternal employment is also not associated with either diet or physical activity of children. However, our results are well consistent with some recent evidence in Europe (Greve, 2011; Gwozdz et al., 2013), supporting the evidence that maternal employment might not necessarily be detrimental to child adiposity. One tentative explanation is that, the major source of informal childcare in China is grandparents, who are more likely to provide childcare with a high quality. In Chapter 3, we provide an empirical analysis that looks at the association between income and calorie intake via a variety of parametric, nonparametric and semiparametric approaches. By means of panel data settings, we are capable of capturing time-invariant individual heterogeneity. It is worth noting that taking a close look at calorie-income elasticities is crucial and implicative of the effectiveness of income-mediated policies for food security in China. Our findings provide strong evidence that calorie-income elasticities are small, irrespective of using parametric, nonparametric, or semiparametric techniques. Furthermore, these elasticities remain small when taking nonlinearities into consideration, and also for sub-analysis for gender, individuals with differences in calorie intake or even impoverished households. Although calorie-income are small, our results are well in line with some prior studies (Bishop et al., 2010; Lu and Luhrmann, 2012; Shankar, 2010; Zhong et al., 2012), suggesting that households might be quite successful in maintaining calorie intake stable as income changes. Also note, despite the marked increase in income, the Chinese demand for better food quality, food diversity and food safety have amplified (Gale and Huang, 2007; Liu et al., 2013b), instead of an increased demand for calorie intakes. Chapter 4 takes a detailed look at how peer effects are associated with childhood and adolescent obesity in China. It expands the empirical work beyond the Western domain in light of different cultural backgrounds between individualistic and collective societies. Furthermore, it broadens the dominant front of adolescents and adults by analyzing children as well. Note that, understanding peer effects on childhood adiposity is of great significance primarily because, as emphasized by Dishion and Tipsord (2011), children’s consumption behaviors are influenced by their peers. More importantly, childhood adiposity could result in persistent adulthood overweight or obesity (Loh and Li, 2013). In addition, the use of self-perceived perceptions of body weight allows for an exploration of the relation between peer effects and individual perceptions of weight status, thereby providing insights into understanding pathways by which peer effects operate within a relatively broader environment. We provide further evidence that peer effects exist not only among adolescents, but also children, suggesting that the formation of health lifestyles associated with peers is important for young children. In addition, we find that the magnitudes of peer effects change greatly over the distribution of individual BMI and stronger effects are observable at the upper end than at the bottom or median. This finding implies that obese individuals are more vulnerable to peers. Furthermore, females are more susceptible compared to males, which mirrors some U.S studies among adolescents (see, for instance, Trogdon et al., 2008). More importantly, we find that community-level average peer BMI is associated with self-perceived bodyweight in adolescents, providing evidence that a higher average peer BMI is related to the probability of a self-assessed perception of overweigh, in particular, for adolescent girls. All in all, our results support the existence of peer effects on childhood and adolescent obesity, but the magnitudes fall within the broader range for the U.S. adolescent studies using similar specification to ours. Therefore, it implies that peer effects do not necessarily strengthen within a collectivistic society, like China, as in comparison to the counterparts of an individualistic society, like the U.S. In Chapter 5, we provide a comprehensive picture of how long work hours are related to health, using not only subjective but also objective measures. Also, it provides a valuable comparison with existing studies predominantly in the Western world. More importantly, it explores several potential mechanisms through which long work hours could impact upon one’s health. In particular, it investigates the relation between long work hours and specific lifestyles, such as sleep, diet (calorie and fat intakes, time spent food preparation and cooking), physical activities (sports participation and time spent on sedentary activities). Apart from a cross-sectional settings, it also adopts a panel analysis, which allows for controlling for unobserved individual heterogeneity. Because, to the best of our knowledge, the only three studies in China (Fritjers et al., 2009; Verité, 2004; Zhao, 2008) all investigate subjective measures of health via cross-sectional data. We reveal that working above 50 hours per week (31-40 hours per week as the comparison), increases the probability of suffering from high blood pressure, though the effects are relatively small. Also, self-evaluated health is poorer for individuals working long hours compared with those weekly working 31-40 hours, however the effect is not so strong. Eventually, long work hours have various impacts of different aspects of individual lifestyles. Specifically, we cannot find a positive correlation between long work hours and obesity. Nevertheless, long work hours seem to be related to a decreased fat intake and less time spent on sedentary activity like watching TV. But, long work hours decrease the probability of sports participation. In summary, we provide limited evidence that long work hours in China have deleterious influences on health or lifestyles. Therefore, further research needs to explore the potential impacts of long work hours on other health or lifestyle measures. References Bishop, J.A. Liu, H.Y. & Zheng, B.H. 2010. Rising incomes and nutritional inequality in China. . In: BISHOP, J. A. (ed.) Studies in Applied Welfare Analysis: Papers from the Third ECINEQ Meeting. Bingley: Emerald Group Publishing. Dishion, T.J. & Tipsord, J.M. 2011. Peer contagion in child and adolescent social and emotional development. Annual Review of Psychology, 62, 189-214. Fritjers, P. Johnston, D.W. & Meng, X. 2009. The mental health cost of long working hours: the case of rural Chinese migrants. Mimeo. Greve, J. 2011. New results on the effect of maternal work hours on childrens overweight status: does the quality of child care matter? Labour Economics, 18(5), 579-590. Gwozdz, W. Sousa-Poza, A. Reisch, L.A. Ahrens, W. Henauw, S.D. Eiben, G. Fernandéz-Alvira, J.M. Hadjigeorgiou, C. De Henauw, S. Kovács, E. Lauria, F. Veidebaum, T. Williams, G. & Bammann, K. 2013. Maternal employment and childhood obesity - a European perspective. Journal of Health Economics, 32(4), 728-742. Gale, F. & Huang, K.S. 2007. Demand for food quantity and quality in China, Economic Research Report. No.32. Washington D.C. : US Department of Agriculture. Lu, L. & Luhrmann, M. 2012. The impact of Chinese income growth on nutritional outcomes. Available from Liu, R.D. Pieniak, Z. & Verbeke, W. 2013b. Consumers attitude and behaviour towards safe food in China: a review. Food Control, 33(1), 93-104. Loh, C.P. & Li, Q. 2013. Peer effects in adolescent bodyweight: evidence from rural China. Social Science & Medicine, 86, 35-44. Shankar, B. 2010. Socio-economic drivers of overnutrition in China. Journal of Human Nutrition and Dietetics, 23(5), 471-479. Trogdon, J.G. Nonnemaker, J. & Pais, J. 2008. Peer effects in adolescent overweight. Journal of Health Economics, 27(5), 1388-99. Verité 2004. Excessive overtime in Chinese supplier factories: causes, impacts and recommendations for action. Verité Research Paper, Amherst, Massachusetts. Zhong, F.N. Xiang, J. & Zhu, J. 2012. Impact of demographic dynamics on food consumption: a case study of energy intake in China. China Economic Review, 23(4), 1011-1019. Zhao, Z. 2008. Health demand and health determinants in China. Journal of Chinese Economic and Business Studies, 6(1), 77-98.
Interdependenzen zwischen Planungsproblemen : ein multiagentenbasierter Koordinationsansatz
(2016) Schüle, Michael; Kirn, Stefan
In this thesis, interdependencies of planning problems in a supply chain in the context of a civil engineering logistic scenario are analysed. In this construction site scenario there are - within the scheduling of activities - the resource-constrained project scheduling problem (RCPSP) and - within the spatial distribution of activities - the asymmetric traveling salesman problem (ATSP) in an interdependence. The required coordination in order to resolve the impact caused by interdependencies of several planning is address as the core problem in this work. Since the individual planning processes do not consider the optimality of the planning of the respective other planning problem, there arise potentially in terms of the overall system and its objective function from the optimum material deviated solutions, although the isolated solutions of partial problems are optimally possibly. The coordination problem is exacerbated by the asymmetric distribution of information through the supply chain. From the perspective of the supply chain, this has the consequence that the service providers must be closely integrated as autonomous actors throughout all levels of the supply chain. In this context of the contractual relationship between the service providers with potentially different interests the coordination problem is extended to the coordination effort between the potentially autonomous providers. This decentralized decision situation must therefore be considered in the coordination of planning. Thereby software agents provide a suitable approach to represent autonomous, distributed, decentralized logistics systems. Especially the field of agent-based decentralized coordination for decentralized planning of decentralized plans offers this work a perspective to develop an approach for the coordination problem. Specifically, the agent-based coordination approach of the generalized partial global planning (GPGP) is used for the planning and coordination tasks, in which both the process of planning as well as the result of planning is distributed. Based on this method, a coordination approach along the interaction protocol engineering process model is developed. The result represents a coordination protocol. The evaluation is performed using the method of simulation as part of a multi-agent simulation. The simulation model is a reduced version of the construction site scenario. The aim of the simulation is to show that the presented multi-agent system and developed coordination protocol (1) are suitable for the optimization of the interdependent planning problems and (2) showing a sound system behaviour.
Theory-based knowledge acquisition for ontology development
(2016) Scheuermann, Andreas; Kirn, Stefan
This thesis concerns the problem of knowledge acquisition in ontology development. Knowledge acquisition is essential for developing useful ontologies but it is a complex and error-prone task. When capturing specific knowledge about a particular domain of interest, the problem of knowledge acquisition occurs due to linguistic, cognitive, modelling, and methodical difficulties. For overcoming these four difficulties, this research proposes a theory-based knowledge acquisition method. By studying the knowledge base, basic terms and concepts in the areas of ontology, ontology development, and knowledge acquisition are defined. A theoretical analysis of knowledge acquisition identifies linguistic, cognitive, modelling, and methodical difficulties, for which a survey of 15 domain ontologies provides further empirical evidence. A review of existing knowledge acquisition approaches shows their insufficiencies for reducing the problem of knowledge acquisition. As the underpinning example, a description of the domain of transport chains is provided. Correspondingly, a theory in business economics, i.e. the Contingency Approach, is selected. This theory provides the key constructs, relationships, and dependencies that can guide knowledge acquisition in the business domain and, thus, theoretically substantiate knowledge acquisition. Method construction uses an approach from the field of Method Engineering, which defines how to develop a tailored method with respect to specific requirements on method design, functionality, components, and the underlying assumptions. The development of the method for theory-based knowledge acquisition covers the specification of the (method and outcome) metamodel, activity model, outcomes, roles, and techniques. The evaluation comprises two descriptive approaches to demonstrate the proposed method’s utility. First, a criteria-based approach evaluates the method with respect to design-related, functional, and component-related requirements. Second, a scenario-based evaluation applies the method within a scenario from the domain of intermodal transport chains for acquiring knowledge to build a domain ontology. The contribution of this research is a theory-based knowledge acquisition method for ontology development. The application and usefulness of this method is demonstrated for a particular domain (transport chains) and uses a particular theory of business economics (the Contingency Approach).
Incomes and asset poverty dynamics and child health among pastoralists in Northern Kenya
(2016) Mburu, Samuel; Sousa-Poza, Alfonso
In chapter one we identified the levels, sources, and trends of household incomes across the five survey waves. We also estimated and compared the income and asset poverty levels. Income poverty was estimated using imputed household income relative to the adjusted poverty line and asset poverty using a regression-based asset index and tropical livestock units (TLU) per capita. Our results indicate that keeping livestock is still the pastoralists’ main source of livelihood, although there is a notable trend of increasing livelihood diversification, especially among livestock-poor households. Majority of the households (over 70%) are both income and livestock poor with few having escaped poverty within the five-year study period. Disaggregating income and asset poverty also reveals an increasing trend of both structurally poor and stochastically non-poor households. The findings show that the TLU-based asset poverty is a more appropriate measure of asset poverty in a pastoral setting. In chapter two we explored the household welfare dynamics among pastoral households in the study area. First, we developed a microeconomic model to analyze the impact of a shock (e.g., a drought) on the behavioral decisions of pastoralists. Secondly, we estimated the existence of single or multiple dynamic equilibria that may constitute an asset poverty trap. We used the tropical livestock units (TLUs) to establish the shape of asset dynamics to locate the welfare equilibria for the sampled households. We also estimated the household characteristics and covariate environmental factors that influence livestock accumulation over time. We use both non-parametric and semi-parametric techniques to establish the shape of asset accumulation path and determine whether multiple equilibria exist. From the model, we found that a negative shock like a drought leads to an immediate decrease in livestock followed by a smooth reduction in consumption. Because the shock also affects the local economy, it prompts a wage decrease, which reinforces the pastoralist’s incentives to tend his own livestock and reduce time spent in the external labor market. Whereas the pastoralist’s labor time allocation shows a pattern of quick convergence, however, the adjustment of other variables such as consumption and capital takes much longer. Food aid helps in smoothening consumption especially among households with few livestock. We established that livestock assets converge to a single stable equilibrium implying that households remained livestock poor in the short term. Such convergence to a stable equilibrium could result from households with more livestock smoothening their consumption during times of food shortage by drawing on their herds for sale or consumption while livestock poor households smoothen their assets by using coping strategies that do not deplete their few livestock holdings. Poor households thus destabilized their consumption to buffer and protect their few assets for future income and survival. We also found that forage availability and herd diversity influenced livestock accumulation over time. In chapter three we established the extent of malnutrition among children by analyzing the levels of malnutrition among children aged five years and below. Additionally, we estimated the effects of drought, measured by the Normalized Difference Vegetation Index (NDVI), on child health outcomes. When the lack of sufficient rainfall reduces the levels of vegetative greenness, the corresponding lower NDVI values indicate forage scarcity. We followed the approach by Chantarat et al. (2012) and transformed the pure NDVI values to z-scores. We used the average NDVI Z-score values from long dry season (June, July, August, and September) for each survey year, extracted from four regions within Marsabit District. We then proxied the nutritional status of children using the mid-upper arm circumference (MUAC). We adjusted the MUAC for the age and sex of the child by converting the values to a MUAC Z-score based on WHO growth charts, as Z-scores are found to be better indicators of wasting than the fixed cut-off value (WHO 2009). The results show that malnutrition among children is prevalent in the study area, with approximately 20% of the children being malnourished and a one standard deviation increase in NDVI z-score decreases the probability of child malnourishment by 12–16 percent. The livestock insurance seems to be an effective risk management tool, as it slightly reduces the probability of malnutrition among children. Child health is also impacted by local conditions and family characteristics, which leave older children worse off than younger siblings who are still being breastfed or receive better care. In the most vulnerable households, boys are worse off than girls. At the same time, male-headed households tend to have healthier children, while family size is negatively associated with child MUAC. To reduce the effects of drought on child malnutrition, the targeting of food aid beneficiaries is crucial, and the use of remote sensing data could improve the effectiveness of these interventions. In chapter four we sought to understand the levels of school enrolment and gender differences in schooling given the challenges of accessibility to schools in the pastoral areas. First, we established levels of school enrolment by gender. Secondly, we estimated the effect of herd migration on school attendance and thirdly we gathered the community perceptions about challenges that school going children face and how they can be addressed. We used both household panel data for children aged between 6 and 15 years and community data obtained from some focus group discussions. Results showed that the effect of herd migration on school attendance is significant and negative: once other factors are controlled for, the predicted probability of child failure to attend school is 26% for households that migrate their livestock. On the other hand, attendance is positively impacted by the educational level of both the household head and his spouse. The analysis of survey data indicates that over the five years studied, school enrollment increased for both boys and girls, averaging 63.6% and 69.0%, respectively, in 2013. During the same period, the school dropout rate was quite low (less than 10%) although still higher among boys than among girls. The mean schooling efficiency (relative grade attained) was 0.67, which implies inefficiency in grade progression. Girls were better off than boys in terms of both grade attainment and staying in school, while children from more educated families showed a higher schooling efficiency than those from less educated families. At the same time, boys are less likely to attend school than girls, probably, the FGD participants confirmed, because boys engage in more economically valued activities like herding, which raises the opportunity costs of their absence for school. Girls, in contrast, engaged mostly in nonmonetizable household duties. Nevertheless, as key barriers to school attendance, the participants identified too few schools, nomadism and communal conflicts.
Economic problems of health insurance : reforms and competition
(2016) Lange, Renate; Schiller, Jörg
Although most modern societies agree that everyone should receive adequate access to medical treatment, health care systems worldwide vary greatly in terms of financing of health care costs, the provision of medical services, and regulatory aspects. Rising costs, economic downturns, and the demographic development have embraced the call for change particularly with regard to financing of health care costs and access to health insurance. Most health care systems have developed historically, but underwent fundamental changes as a consequence of policy decisions and reforms. Looking back on recent health reforms in the U.S. and Germany two divergent trends can be observed: Over the last two decades, German Statutory Health Insurance (SHI) primarily experienced benefit cuts and had to implement economic incentives and market-based instruments to a solidary-based social security model in order to overall contain costs. At the same time, recent health reforms in the U.S. have shown that a solely market-based health insurance system is hardly consistent with modern society’s ideas on fairness and distributive justice. Furthermore, the exclusion of large parts of the population from seeking health insurance as a result of high premiums is not only associated with high costs and negative effects (even for those holding insurance coverage), but overall seen as highly inefficient. This thesis aims to draw a comprehensive picture of economic problems of health insurance and, thereby, assesses economic goals and analyzes effects of recent health reforms in the two historically grown very different health insurance systems of Germany and the U.S. More specifically, three research questions will be addressed: First, looking at the demand for supplemental health insurance (SuppHI) in the aftermath of benefit reductions in German SHI, it investigates what factors drive the demand for SuppHI and what are possible sources of selection. Furthermore, this thesis offers new insights on what the two health insurance systems can learn and take over from each other. In this context, it discusses how new trends in health insurance in the U.S. (i.e. Health Savings Accounts (HSAs)) could be implemented in German SHI. The third focus of this thesis is on the mutual interdependence of public and private health insurance markets. Analyzing financial data of private health insurers in the U.S., it looks into the question of how premiums in Private Health Insurance (PHI) are affected by public health insurance programs (i.e. Medicaid).
Fuel for life : domestic cooking fuels and women’s health in rural China?
(2016) Xue, Jianhong; Sousa-Poza, Alfonso; Nie, Peng
Using longitudinal and biomarker data from the China Family Panel Studies and the China Health and Nutrition Survey, this study examines the association between the type of domestic cooking fuel and the health of women aged ≥16 in rural China. Regarding three major domestic cooking fuels (wood/straw, coal and liquefied natural gas (LNG)), we find that, compared to women whose households cook with dirty fuels like wood/straw, women whose households cook with cleaner fuels like LNG have a significantly lower probability of chronic or acute diseases and are more likely to report better health. Even after controlling for unobserved individual heterogeneity, we find some evidence that women in households cooking with LNG are less likely to suffer from chronic/acute diseases. Cooking with domestic coal instead of wood or straw is also associated with elevated levels of having certain risks (such as systolic and diastolic blood pressure) related to cardiovascular diseases.
Food insecurity among older Europeans : evidence from the survey of health, ageing, and retirement in Europe
(2016) Sousa-Poza, Alfonso; Nie, Peng
Using data from the fifth wave of the Survey of Health, Ageing and Retirement in Europe, this study investigates the association between food insecurity (FI) and several demographic, socioeconomic, and health-related characteristics in a sample of European residents aged 50 and over. Our initial analysis reveals that in 2013, the proportions of 50+ individuals reporting an inability to afford meat/fish/poultry or fruit/vegetables more than 3 times per week were 11.1% and 12.6%, respectively. It also indicates that not only income but also functional impairment and chronic disease are significantly associated with an increased probability of food insecurity. In a subsequent nonlinear decompositional analysis of the food unaffordability gap between European countries with high versus low FI prevalence, our rich set of covariates explains 36–39% of intercountry differences, with household income, being employed, and having functional impairment and/or chronic disease as the most important contributors.
Investor sentiment in blogs : design of a classifier and validation by a portfolio simulation
(2016) Klein, Achim; Kirn, Stefan
How can investment recommendations available on the web significantly improve stock selection? This dissertation shows how online investment recommendations can automatically be analyzed, aggregated, and used to achieve a return above the market’s. To this respect, it is crucial to understand how investment recommendations affect returns. Therefore, the dissertation examines the effects of direct and indirect investment recommendations from blogs in the form of investor sentiments (i.e., opinions) on the expected development of stock prices. Blogs have made it possible for everyone to publish articles on the web. The studied blog platforms Seekingalpha and Blogspot host a wealth of semi-professional stock analyses, investor opinions, company rumors, and stock recommendations. The dissertation’s study uses about 77,000 articles from Seekingalpha and about 198,000 articles from Blogspot over a five-year period (2007-2011). A novel text classification method is developed for the automatic classification of blog articles in a positive vs. negative sentiment. To achieve a high classification accuracy, experiments were carried out to configure this method. The text classification method uses machine learning techniques, which learn from manually classified articles from a novel corpus. Using behavioral finance theory, hypotheses are developed about the effects of investor sentiments on a portfolios returns. To test these hypotheses, a monthly selection of stocks of the Dow Jones Industrial Average into a portfolio was simulated (i.e., backtested). The selection is made by means of the ranking of the monthly aggregated overall sentiment of all articles regarding a specific stock. The results show that a return above the market’s can be achieved with aggregated investor sentiments from the Seekingalpha platform. In most cases, the achieved return exceeds the return of a momentum portfolio based solely on past returns. For the platform Blogspot, results are weaker. Overall, it seems advisable for investors to select a small number of stocks based on the most positive and most negative monthly investor sentiments from professional blogs.

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