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Showing papers by "Tilburg University published in 2009"


01 Jan 2009
TL;DR: The results of the experiments reveal that nonlinear techniques perform well on selected artificial tasks, but that this strong performance does not necessarily extend to real-world tasks.
Abstract: In recent years, a variety of nonlinear dimensionality reduction techniques have been proposed that aim to address the limitations of traditional techniques such as PCA and classical scaling. The paper presents a review and systematic comparison of these techniques. The performances of the nonlinear techniques are investigated on artificial and natural tasks. The results of the experiments reveal that nonlinear techniques perform well on selected artificial tasks, but that this strong performance does not necessarily extend to real-world tasks. The paper explains these results by identifying weaknesses of current nonlinear techniques, and suggests how the performance of nonlinear dimensionality reduction techniques may be improved.

2,141 citations


Journal ArticleDOI
Klaas Sijtsma1
TL;DR: This discussion paper argues that both the use of Cronbach’s alpha as a reliability estimate and as a measure of internal consistency suffer from major problems.
Abstract: This discussion paper argues that both the use of Cronbach’s alpha as a reliability estimate and as a measure of internal consistency suffer from major problems. First, alpha always has a value, which cannot be equal to the test score’s reliability given the interitem covariance matrix and the usual assumptions about measurement error. Second, in practice, alpha is used more often as a measure of the test’s internal consistency than as an estimate of reliability. However, it can be shown easily that alpha is unrelated to the internal structure of the test. It is further discussed that statistics based on a single test administration do not convey much information about the accuracy of individuals’ test performance. The paper ends with a list of conclusions about the usefulness of alpha.

2,017 citations


Journal ArticleDOI
TL;DR: In this paper, the basic Kriging assumptions and formulas are presented and compared with classic linear regression metamodels and bootstrapping to estimate the variance of the kriging predictor.

888 citations


BookDOI
TL;DR: In this article, the authors introduce the updated and expanded version of the Financial Development and Structure Database and present recent trends in structure and development of financial institutions and markets across countries, adding indicators on banking structure and financial globalization.
Abstract: This paper introduces the updated and expanded version of the Financial Development and Structure Database and presents recent trends in structure and development of financial institutions and markets across countries. The authors add indicators on banking structure and financial globalization. They find a deepening of both financial markets and institutions, a trend concentrated in high-income countries and more pronounced for markets than for banks. Similarly, the recent increase in cross-border lending and debt issues has been concentrated in high-income countries, while low and lower-middle income countries have experienced an increase in remittance flows. Low net interest margins, rising profitability and declining stability in high-income countries’ banking sectors characterize the recent financial sector boom in high income countries leading up to the global financial crisis of 2007.

856 citations


Journal ArticleDOI
TL;DR: Overall, banking strategies that rely prominently on generating noninterest income or attracting nondeposit funding are very risky, consistent with the demise of the US investment banking sector.
Abstract: This paper examines the implications of bank activity and short-term funding strategies for bank risk and return using an international sample of 1334 banks in 101 countries leading up to the 2007 financial crisis. Expansion into non-interest income generating activities such as trading increases the rate of return on assets, and it may offer some risk diversification benefits at very low levels. Non-deposit, wholesale funding in contrast lowers the rate of return on assets, while it can offer some risk reduction at commonly observed low levels of non-deposit funding. A sizeable proportion of banks, however, attract most of their short-term funding in the form of non-deposits at a cost of enhanced bank fragility. Overall, banking strategies that rely prominently on generating non-interest income or attracting non-deposit funding are very risky, consistent with the demise of the U.S. investment banking sector.

751 citations


Journal ArticleDOI
TL;DR: The newly developed Compulsive Internet Use Scale (CIUS) contains 14 items ratable on a 5-point Likert scale and showed good factorial stability across time and across different samples and subsamples.
Abstract: The present study aimed to develop a short, easily administered, psychometrically sound, and valid instrument to assess the severity of compulsive Internet use. A set of criteria was determined based on the addiction literature. Next, the internal consistency and convergent validity were determined, and the set was tested as a one-factor solution in two representative samples of heavy Internet users (n = 447 and n = 229) and in one large convenience sample of regular Internet users (n = 16,925). In these three studies, respondents were asked about their online behavior and about problems related to Internet use. In the first study, the Online Cognition Scale (OCS) was included to determine concurrent validity. The newly developed Compulsive Internet Use Scale (CIUS) contains 14 items ratable on a 5-point Likert scale. The instrument showed good factorial stability across time and across different samples and subsamples. The internal consistency is high, and high correlations with concurrent and c...

725 citations


Journal ArticleDOI
Jaap Paauwe1
TL;DR: The relationship between HRM and performance has been examined from a variety of perspectives rooted in organizational behaviour, sociology, economics, industrial relations and organizational psychology, with a particular emphasis placed on the impact of various combinations of human resource practices on a range of performance outcomes at the individual and organizational level of analysis.
Abstract: Twenty years ago Guest (1987) published his normative framework describing the essence of HRM. He presented HRM as a new approach to personnel management, emphasizing its strategic contribution, its closer alignment to business, the involvement of line management, and focusing on HRM outcomes like commitment, flexibility and quality. The achievement of these human resource outcomes was, in turn, expected to contribute to a range of positive organizational outcomes, including high job performance, low turnover, low absence and high cost-effectiveness through the full utilization of employees, now relabelled as human resources. Put this way, it is not difficult to understand the wide appeal that the notion of HRM had (and still has) to academics and practitioners alike. It led to the renaming of chairs/departments within universities and to changed job titles in the business community. The attractiveness of the concept of HRM increased considerably when Huselid, in 1995, published a ground-breaking paper in the Academy of Management Journal in which he demonstrated a correlation between the degree of sophistication of HR-systems and the market value per employee among a range of publicly quoted companies in the USA. The paper generated admiration, criticism and an abundance of 'me too' research, trying to replicate the proclaimed relationship between HRM and Performance (Delery and Doty, 1996; Guthrie, 2001; Koch and McGrath, 1996; Wright et al., 2003). Since then many academics on both sides of the Atlantic have become active in this field, with a special focus on the relationship between HRM and Performance. Within this rapidly expanding field of study, the HRM–Performance relationship has been approached from a variety of perspectives rooted in organizational behaviour, sociology, economics, industrial relations and organizational psychology, with a particular emphasis placed on the impact of various combinations of human resource practices on a range of performance outcomes at the individual and organizational level of analysis.

684 citations


Journal ArticleDOI
TL;DR: It is concluded that two-system models currently provide little scientific advance, and researchers are encouraged to adopt more rigorous conceptual definitions and employ more stringent criteria for testing the empirical evidence in support for two- system theories.
Abstract: Over the past two decades, there has been an upsurge in theoretical frameworks alluding to the existence of two different processing systems that supposedly operate according to different rules. This article critically examines the scientific advance offered by these theories (in particular advances in the domains of reasoning, decision making, and social cognition) and questions their theoretical coherence as well as the evidence for their existence. We scrutinize the conceptual underpinnings of two-system models and explicate the assumptions underlying these models to see whether they are reasonable. We also evaluate the empirical paradigms used to validate two-system models and ponder about their explanatory strength and predictive power. Given the popularity of these models, we discuss the appeal of two-system theories and suggest potential reasons for their prevalence. We comment on the potential costs associated with these models and allude to the desired nature of potential alternatives. We conclude that two-system models currently provide little scientific advance, and we encourage researchers to adopt more rigorous conceptual definitions and employ more stringent criteria for testing the empirical evidence in support for two-system theories.

559 citations


Journal ArticleDOI
TL;DR: In this article, the authors consider the transactional characteristics of complementary local assets and model foreign market entry as the optimal assignment of equity between their owners and MNEs, and predict whether equity will be held by MNE or by local firms, or shared between them.
Abstract: Both Anderson and Gatignon and the Uppsala internationalization model see the initial mode of foreign market entry and subsequent modes of operation as unilaterally determined by multinational enterprises (MNEs) arbitraging control and risk and increasing their commitment as they gain experience in the target market. OLI and internalization models do recognize that foreign market entry requires the bundling of MNE and complementary local assets, which they call location or country-specific advantages, but implicitly assume that those assets are freely accessible to MNEs. In contrast to both of these MNE-centric views, I explicitly consider the transactional characteristics of complementary local assets and model foreign market entry as the optimal assignment of equity between their owners and MNEs. By looking at the relative efficiency of the different markets in which MNE and complementary local assets are traded, and at how these two categories of assets match, I am able to predict whether equity will be held by MNEs or by local firms, or shared between them, and whether MNEs will enter through greenfields, brownfields, or acquisitions. The bundling model I propose has interesting implications for the evolution of the MNE footprint in host countries, and for the reasons behind the emergence of Dragon MNEs.

517 citations


Journal ArticleDOI
01 Jun 2009-Emotion
TL;DR: This research empirically supports the distinction between two qualitatively different types of envy, namely benign and malicious envy, and reveals that the experience of benign envy leads to a moving-up motivation aimed at improving one's own position, whereas the experience at damaging the position of the superior other.
Abstract: Envy is the painful emotion caused by the good fortune of others. This research empirically supports the distinction between two qualitatively different types of envy, namely benign and malicious envy. It reveals that the experience of benign envy leads to a moving-up motivation aimed at improving one's own position, whereas the experience of malicious envy leads to a pulling-down motivation aimed at damaging the position of the superior other. Study 1 used guided recall of the two envy types in a culture (the Netherlands) that has separate words for benign and malicious envy. Analyses of the experiential content of these emotions found the predicted differences. Study 2 and 3 used one sample from the United States and one from Spain, respectively, where a single word exists for both envy types. A latent class analysis based on the experiential content of envy confirmed the existence of separate experiences of benign and malicious envy in both these cultures as well. The authors discuss the implications of distinguishing the two envy types for theories of cooperation, group performance, and Schadenfreude.

441 citations


Journal ArticleDOI
TL;DR: As the barriers largely differ within guidelines, tailored and barrier-driven implementation strategies focusing on key recommendations are needed to improve adherence in practice.
Abstract: Background Despite wide distribution and promotion of clinical practice guidelines, adherence among Dutch general practitioners (GPs) is not optimal. To improve adherence to guidelines, an analysis of barriers to implementation is advocated. Because different recommendations within a guideline can have different barriers, in this study we focus on key recommendations rather than guidelines as a whole, and explore the barriers to implementation perceived by Dutch GPs.

Journal ArticleDOI
TL;DR: An overview of lean thinking and its application to health care is presented, believing lean thinking has the potential to improve health care delivery and there are methodological and practical considerations that need to be taken into account.
Abstract: Background. Incidents and quality problems are a prime cause why health care leaders are calling to redesign health care delivery. One of the concepts used is lean thinking. Yet, lean often leads to resistance. Also, there is a lack of high quality evidence supporting lean premises. In this paper, we present an overview of lean thinking and its application to health care. Development, theory and application of lean thinking to health care. Lean thinking evolved from a tool designed to improve operational shop-floor performance at an automotive manufacturer to a management approach with both operational and sociotechnical aspects. Sociotechnical dynamics have until recently not received much attention. At the same time a balanced approach might lead to a situation where operational and sociotechnial improvements are mutually reinforcing. Application to health care has been limited and focussed mainly on operational aspects using original lean tools. A more integrative approach would be to pay more attention to sociotechnical dynamics of lean implementation efforts. Also, the need to use the original lean tools may be limited, because health care may have different instruments and tools already in use that are in line with lean thinking principles. Discussion. We believe lean thinking has the potential to improve health care delivery. At the same time, there are methodological and practical considerations that need to be taken into account. Otherwise, lean implementation will be superficial and fail, adding to existing resistance and making it more difficult to improve health care in the long term.

Journal ArticleDOI
TL;DR: In this paper, the decisions that management researchers made in 69 meta-analytic studies published between 1980 and 2007 in 14 management journals were reviewed. And four meta-analyses of relationships that have been studied with varying frequency in management research, to provide empirical evidence that metaanalytical decisions influence results.

Journal ArticleDOI
TL;DR: This review demonstrates that Dutch evidence-based clinical guidelines can be effective in improving the process and structure of care, and highlights the need for well-designed studies focusing on the level of the recommendations to determine which factors influence guideline utilisation and improved patient outcomes.
Abstract: Background: Evidence-based clinical guidelines aim to improve the quality of care. In The Netherlands, considerable time and effort have been invested in the development and implementation of evidence-based guidelines since the 1990s. Thus far, no reviews are available on their effectiveness. The primary aim of this article was to assess the evidence for the effectiveness of Dutch evidence-based clinical guidelines in improving the quality of care. Methods: A systematic review of studies evaluating the effects of Dutch evidence-based guidelines on both the process and structure of care and patient outcomes was conducted. The electronic databases Medline and Embase (1990–2007) and relevant scientific journals were searched. Studies were only selected if they included a controlled trial, an interrupted time series design or a before and after design. Results: A total of 20 studies were included. In 17 of 19 studies that measured the effects on the process or structure of care, significant improvements were reported. Thirteen of these studies reported improvement with respect to some of the recommendations studied. In addition, the size of the observed effects varied largely across the recommendations within guidelines. Six of nine studies that measured patient health outcomes showed significant but small improvements as a result of the use of clinical guidelines. Conclusions: This review demonstrates that Dutch evidence-based clinical guidelines can be effective in improving the process and structure of care. The effects of guidelines on patient health outcomes were studied far less and data are less convincing. The high level of variation in effects across recommendations suggests that implementation strategies tailored to individual recommendations within the guideline are needed to establish relevant improvements in healthcare. Moreover, the results highlight the need for well-designed studies focusing on the level of the recommendations to determine which factors influence guideline utilisation and improved patient outcomes.

Journal ArticleDOI
TL;DR: In this article, social interaction between managers from different units of a multinational enterprise (MNE) has been shown to be an important factor stimulating intra-MNE knowledge-sharing.
Abstract: Social interaction between managers from different units of a multinational enterprise (MNE) has been shown to be an important factor stimulating intra-MNE knowledge-sharing. Face-to-face social interactions form a communication channel particularly conducive to the transfer of tacit, non-codified knowledge. But intensive social interaction also provides opportunities for social construction of knowledge in a learning dialogue. The first explanation (sender–receiver) makes us expect social interaction to moderate positively the effects of the factors giving rise to knowledge flows in the first place, such as differences in capabilities between MNE subsidiaries. The second perspective (social learning) also grants an independent effect to social interaction as a main factor stimulating intra-MNE knowledge flows. We formulate hypotheses based on both perspectives, and test these on data from 169 MNE subsidiaries. Our findings show a considerable main effect of social interaction on all intra-MNE knowledge flows, confirming the expectations based on the social learning model. Interaction effects, based on the predictions of the sender–receiver model, are only partly confirmed. These findings suggest that future research should devote more attention to the social constitution of MNE knowledge.

Journal ArticleDOI
TL;DR: In this paper, it is rather puzzling that given the massive interest in affective neuroscience in the last decade, it still seems to make sense to raise the question "Why bodies" and to try to provide...
Abstract: Why bodies? It is rather puzzling that given the massive interest in affective neuroscience in the last decade, it still seems to make sense to raise the question ‘Why bodies’ and to try to provide...

Journal ArticleDOI
TL;DR: Results of the experiments suggest that alternating the order of nonlinearity of GP individuals with their structural complexity produces solutions that are both compact and have smoother response surfaces, and, hence, contributes to better interpretability and understanding.
Abstract: This paper presents a novel approach to generate data-driven regression models that not only give reliable prediction of the observed data but also have smoother response surfaces and extra generalization capabilities with respect to extrapolation. These models are obtained as solutions of a genetic programming (GP) process, where selection is guided by a tradeoff between two competing objectives - numerical accuracy and the order of nonlinearity. The latter is a novel complexity measure that adopts the notion of the minimal degree of the best-fit polynomial, approximating an analytical function with a certain precision. Using nine regression problems, this paper presents and illustrates two different strategies for the use of the order of nonlinearity in symbolic regression via GP. The combination of optimization of the order of nonlinearity together with the numerical accuracy strongly outperforms ldquoconventionalrdquo optimization of a size-related expressional complexity and the accuracy with respect to extrapolative capabilities of solutions on all nine test problems. In addition to exploiting the new complexity measure, this paper also introduces a novel heuristic of alternating several optimization objectives in a 2-D optimization framework. Alternating the objectives at each generation in such a way allows us to exploit the effectiveness of 2-D optimization when more than two objectives are of interest (in this paper, these are accuracy, expressional complexity, and the order of nonlinearity). Results of the experiments on all test problems suggest that alternating the order of nonlinearity of GP individuals with their structural complexity produces solutions that are both compact and have smoother response surfaces, and, hence, contributes to better interpretability and understanding.

Journal ArticleDOI
11 Sep 2009-Science
TL;DR: The core of the problem is inducing cooperation in situations where individuals and nations will collectively gain if all cooperate, but each faces the temptation to take a free ride on the cooperation of others.
Abstract: Energy, food, and water crises; climate disruption; declining fisheries; increasing ocean acidification; emerging diseases; and increasing antibiotic resistance are examples of serious, intertwined global-scale challenges spawned by the accelerating scale of human activity. They are outpacing the development of institutions to deal with them and their many interactive effects. The core of the problem is inducing cooperation in situations where individuals and nations will collectively gain if all cooperate, but each faces the temptation to take a free ride on the cooperation of others. The nation-state achieves cooperation by the exercise of sovereign power within its boundaries. The difficulty to date is that transnational institutions provide, at best, only partial solutions, and implementation of even these solutions can be undermined by internation competition and recalcitrance.

Posted Content
TL;DR: In this paper, the authors derive an equilibrium asset pricing model incorporating liquidity risk, derivative assets, and short-selling due to hedging of non-traded risk, and find strong evidence for an expected liquidity premium earned by the credit protection seller.
Abstract: We derive an equilibrium asset pricing model incorporating liquidity risk, derivative assets, and short-selling due to hedging of non-traded risk. We show that, both for positive-net-supply assets and derivatives, the sign of liquidity effects depends on investor heterogeneity in non-traded risk exposure, risk aversion, horizon and wealth. We also show that liquidity risk affects derivatives in a different way than positive-net-supply assets. We estimate this model for the credit default swap market using GMM. We find strong evidence for an expected liquidity premium earned by the credit protection seller. The effect of liquidity risk is significant but economically small.

Journal ArticleDOI
TL;DR: In this article, a panel of 60,000 firm-year observations on listed and unlisted companies in Eastern European economies was used to assess the differential impact of foreign bank lending on firm growth and financing.
Abstract: While the positive growth effects of financial integration are extensively documented, little is known of its impact on small and young firms. This paper aims to fill this void relying on a panel of 60,000 firm-year observations on listed and unlisted companies in Eastern European economies to assess the differential impact of foreign bank lending on firm growth and financing. Foreign lending stimulates growth in firm sales, assets, and use of financial debt even though the effect is dampened for small firms. More strikingly, young firms benefit most from foreign bank presence, while businesses connected to domestic banks or to the government suffer. Overall, our findings suggest that foreign banks can help to mitigate connected-lending problems and to improve capital allocation.

Journal ArticleDOI
TL;DR: Emotional contagion represents an instance of truly affective reactions that may be mediated by visual pathways of old evolutionary origin bypassing cortical vision while still providing a cornerstone for emotion communication and affect sharing.
Abstract: The spontaneous tendency to synchronize our facial expressions with those of others is often termed emotional contagion. It is unclear, however, whether emotional contagion depends on visual awareness of the eliciting stimulus and which processes underlie the unfolding of expressive reactions in the observer. It has been suggested either that emotional contagion is driven by motor imitation (i.e., mimicry), or that it is one observable aspect of the emotional state arising when we see the corresponding emotion in others. Emotional contagion reactions to different classes of consciously seen and "unseen" stimuli were compared by presenting pictures of facial or bodily expressions either to the intact or blind visual field of two patients with unilateral destruction of the visual cortex and ensuing phenomenal blindness. Facial reactions were recorded using electromyography, and arousal responses were measured with pupil dilatation. Passive exposure to unseen expressions evoked faster facial reactions and higher arousal compared with seen stimuli, therefore indicating that emotional contagion occurs also when the triggering stimulus cannot be consciously perceived because of cortical blindness. Furthermore, stimuli that are very different in their visual characteristics, such as facial and bodily gestures, induced highly similar expressive responses. This shows that the patients did not simply imitate the motor pattern observed in the stimuli, but resonated to their affective meaning. Emotional contagion thus represents an instance of truly affective reactions that may be mediated by visual pathways of old evolutionary origin bypassing cortical vision while still providing a cornerstone for emotion communication and affect sharing.

Journal ArticleDOI
TL;DR: In this article, a study among 702 Dutch employees working in the health care and welfare sector examined individual and organizational factors that are related to workers' employability orientation and turnover intention, and push and pull motives were examined of employees who aimed to leave their job.
Abstract: This study among 702 Dutch employees working in the health care and welfare sector examined individual and organizational factors that are related to workers' employability orientation and turnover intention. Additionally, push and pull motives were examined of employees who aimed to leave their job. Results indicated that a strong employability culture adds extra variance over and above individual factors such as career satisfaction and role breadth self-efficacy in the explanation of employability orientation, turnover intention, and push motives of employees who aim to leave their job. That is, employability culture is positively related to employability orientation, but negatively related to turnover intention and to push motives of those who aim to leave. Pull motives of employees who want to leave are explained by individual factors only, such as career dissatisfaction and role breadth self-efficacy, but not by employability culture. These findings suggest that organizations that need to adapt to changing environments should implement a strong employability culture, because such a culture stimulates employability orientations among their employees while simultaneously decreasing turnover intentions.

Journal ArticleDOI
TL;DR: In this article, a survey of more than 1,100 innovative firms in Germany found that public procurement and knowledge spillovers from universities propel innovation success equally. But the benefits of university knowledge apply uniformly to all firms.

Journal ArticleDOI
TL;DR: A new integral operational definition of frailty was developed and this operational definition lies at the heart of an integral conceptual working model ofFrailty, which expresses the relationships between three domains of Frailty, adverse outcomes such as disability and the determinants.
Abstract: Objectives: Most conceptual and operational definitions of frailty place heavy emphasis on the physical problems encountered by older people. The accompanying models are based largely on a medical model. An integral approach is almost never adopted. This study aims to develop both an integral operational definition of frailty and an integral conceptual model of frailty. Design: In order to achieve these aims, a thorough literature search was performed on components of operational definitions and models of frailty. In addition, experts (N=17) were consulted during two expert meetings. Results: There was consensus among the experts on the inclusion of the following components in the operational definition of frailty: strength, balance, nutrition, endurance, mobility, physical activity and cognition. Some respondents indicated that they would wish to add components from the psychological or social domain. Supported by results from the literature search, a new integral operational definition of frailty was developed. This operational definition lies at the heart of an integral conceptual working model of frailty. This model expresses the relationships between three domains of frailty, adverse outcomes such as disability and the determinants. Conclusion: The model should be able to serve as a basis for further scientific research on frailty. The model also provides a framework for the development of a measurement instrument which can be used for the identification of frail elderly persons.

Journal ArticleDOI
TL;DR: A longitudinal dataset of 65 biomedical scientists at a New Zealand university and coded collaboration variables by hand checking each of their publications in a period of 14 years found that at article level, both within-university collaboration and international collaboration are positively related to an article's quality and that, at scientist-year level, only international collaboration is positive related to a scientist's future research output.

Journal ArticleDOI
TL;DR: Cognitive and emotional regulation difficulties affect functioning of moderately preterm children, as school problems, a slightly lower IQ, attention and behavioral problems are found when they are compared with term-born children.
Abstract: OBJECTIVE: To study outcome of low-risk moderately preterm birth between 32 and 36/7 weeks9 gestation. METHODS: 377 Moderately preterm children (M: 34.7, SD: 1.2 complete weeks), without need for neonatal intensive care and without dysmaturity or congenital malformations, were compared with 182 term children and assessed at eight years (M: 8.9, SD: 0.54). School situation, IQ, sustained attention, behavior problems, and attention-deficit/hyperactivity characteristics were studied. RESULTS: Special education was attended by 7.7% of the moderately preterm children, more than twice the rate of 2.8% in the general Dutch population of this age. Additional exploration for two preterm subgroups of 32 to 33 versus 34 to 36 weeks9 gestation showed a need for special education in 9.7% versus 7.3% and a significant difference in grade retention for 30% versus 17%, respectively. Of the children attending mainstream primary schools, grade retention was found in 19% of the preterm versus 8% of the comparison children. Adjusting for maternal education, a group difference of 3 points was found in IQ. The preterm children needed more time for the sustained attention task. The preterm children had more behavior problems (specifically internalizing problems with 27% scoring above the borderline cut-off), as well as more attention-deficit/hyperactivity disorder characteristics (specifically attention deficits). CONCLUSIONS: Cognitive and emotional regulation difficulties affect functioning of moderately preterm children, as school problems, a slightly lower IQ, attention and behavioral problems are found when they are compared with term-born children. Identification and monitoring of precursors of these problems at younger age is needed in view of prevention purposes.

Journal ArticleDOI
TL;DR: Among 1,000 German brokerage clients, investors who report enjoying investing or gambling turn over their portfolio at twice the rate of their peers, suggesting nonpecuniary benefits of trading offer a straightforward explanation of the “excessive trading puzzle.”
Abstract: Among 1,000 German brokerage clients for whom both survey responses and actual trading records are available, investors who report enjoying investing or gambling turn over their portfolio at twice the rate of their peers. Including entertainment attributes as additional explanatory variables in cross-sectional regressions of portfolio turnover on objective investor attributes more than doubles the fraction of the total variation of portfolio turnover that can be explained. The results are robust to controlling for gender and proxies for overconfidence constructed from survey responses. Nonpecuniary benefits of trading thus appear to offer a straightforward explanation of the “excessive trading puzzle.”

Journal ArticleDOI
TL;DR: This article generalized scoring rules to non-expected utility theories of risk and ambiguity, yielding mutual benefits: users of scoring rules can benefit from the empirical realism of nonexpected utility, and analysts of ambiguity attitudes can benefit by efficient measurements using proper scoring rules.
Abstract: Proper scoring rules provide convenient and highly efficient tools for incentive-compatible elicitations of subjective beliefs. As traditionally used, however, they are valid only under expected value maximization. This paper shows how they can be generalized to modern ("non-expected utility") theories of risk and ambiguity, yielding mutual benefits: users of scoring rules can benefit from the empirical realism of non-expected utility, and analysts of ambiguity attitudes can benefit from efficient measurements using proper scoring rules. An experiment demonstrates the feasibility of our generalization.

Journal ArticleDOI
TL;DR: In this paper, van Dam et al. gave a survey of answers to the question of which graphs are determined by the spectrum of some matrix associated to the graph and formulated some research questions on the topic.

Journal ArticleDOI
TL;DR: In this paper, the authors assess whether there is a gap in well-being between unmarried cohabitants and the married, and if selection factors can explain this so-called cohabitation gap.
Abstract: The study aims to assess, first, whether there is a gap in well-being between unmarried cohabitants and the married, second, if selection factors can explain this so-called cohabitation gap, and third, if the size of the cohabitation gap differs across countries and how this can be explained. We use pooled data from young adults (18–44) in 3 rounds of the European Social Survey (N ≅ 31, 500). Multilevel regression analyses show that there is a moderate cohabitation gap that can be partly explained with the selection factors material resources and religiosity. Country differences were clear and could partly be explained with the level of institutionalization: In countries where cohabitation is more accepted and more prevalent, the cohabitation gap is smaller.