Derivation of the theoretical autocovariance and autocorrelation function of autoregessive moving average processes

Closed form expressions for the theoretical autocovariance and autocorrelation function of mixed autoregressive moving average processes are presented. The results provide insight into the construction of autocovariances and autocorrelatians and are useful in theoretical analysis, model identification as well as in implementing maximum likelihood estimation algorithms.     

Foundations and Their Institutional Context: Cross-Evaluating Evidence from Germany and the United States

According to the relevant literature, the relationship between government and the private foundation sector in Germany is marked by a paradigm of conflict very similar to the one that has often dominated the U.S. discussion of government/nonprofit relationships in the past. More specifically, scholars often hold that the development of foundations in Germany is largely hampered by an administrative and regulatory climate that weakens rather than strengthens the foundation community. Two main arguments are brought forth in this context: First, the expansion of the state bureaucracy into traditional activity fields of foundations crowds out the foundation sector; second, the structure of tax regulations is detrimental to a sound development of foundations. However, while these arguments figure prominently in the policy debate, they have neither empirically nor analytically been substantiated as of yet. Borrowing from organizational theory, this article critically evaluates the arguments in the light of available evidence in an effort to contribute to a better understanding of foundations in an international context.     

“How powerful is demography? The serendipity theorem revisited” comment on De la Croix et al. (2012)

Samuelson’s (Int Econ Rev 16(3):531-538, 1975) serendipity theorem states that the “goldenest golden rule” steady-state equilibrium can be obtained by a competitive two-period overlapping generation economy with capital accumulation, provided that the optimal growth rate prevails. De la Croix et al. (J Popul Econ 25:899-922, 2012) extended the scope of the theorem by showing that it also holds for risky lifetime. With this note, we introduce medical expenditure as a determinant of the probability of surviving to old age to prove the theorem. The original as well as all extended versions of the serendipity theorem, however, fail to prove that second-order conditions are satisfied in general. Still, unlike De la Croix et al. (J Popul Econ 25:899-922, 2012), we can exclude the existence of corner solutions where the probability of reaching old age is zero or one. The zero survival probability case becomes irrelevant if the option to randomize between death and life utility is taken into account. Survival with certainty is ruled out if the marginal cost of survival is increasing. Hence, the optimal survival probability represents an interior solution. Furthermore, we show for the optimal survival probability that the value of a statistical life is positive and equal to its marginal cost.     

Patients-in-waiting: Living between sickness and health in the genomics era

What are the social consequences of the recent expansion of newborn screening in the United States? The adoption of new screening technologies has generated diagnostic uncertainty about the nature of screening targets, making it unclear not only whether a newborn will develop a disease but also what the condition actually is. Based on observations in a genetics clinic and in-depth interviews with parents and geneticists, we examine how parents and clinical staff work out the social significance of uncertain newborn screening results. We find that some newborns will experience a specific trajectory of prolonged liminality between a state of normal health and pathology. Based on a review of related literatures, we suggest "patients-in-waiting" as an umbrella concept for those under medical surveillance between health and disease.     

Measuring social dynamics in a massive multiplayer online game

Quantification of human group-behavior has so far defied an empirical, falsifiable approach. This is due to tremendous difficulties in data acquisition of social systems. Massive multiplayer online games (MMOG) provide a fascinating new way of observing hundreds of thousands of simultaneously socially interacting individuals engaged in virtual economic activities. We have compiled a data set consisting of practically all actions of all players over a period of 3 years from a MMOG played by 300,000 people. This large-scale data set of a socio-economic unit contains all social and economic data from a single and coherent source. Players have to generate a virtual income through economic activities to ‘survive’ and are typically engaged in a multitude of social activities offered within the game. Our analysis of high-frequency log files focuses on three types of social networks, and tests a series of social-dynamics hypotheses. In particular we study the structure and dynamics of friend-, enemy- and communication networks. We find striking differences in topological structure between positive (friend) and negative (enemy) tie networks. All networks confirm the recently observed phenomenon of network densification. We propose two approximate social laws in communication networks, the first expressing betweenness centrality as the inverse square of the overlap, the second relating communication strength to the cube of the overlap. These empirical laws provide strong quantitative evidence for the Weak ties hypothesis of Granovetter. Further, the analysis of triad significance profiles validates well-established assertions from social balance theory. We find overrepresentation (underrepresentation) of complete (incomplete) triads in networks of positive ties, and vice versa for networks of negative ties. Empirical transition probabilities between triad classes provide evidence for triadic closure with extraordinarily high precision. For the first time we provide empirical results for large-scale networks of negative social ties. Whenever possible we compare our findings with data from non-virtual human groups and provide further evidence that online game communities serve as a valid model for a wide class of human societies. With this setup we demonstrate the feasibility for establishing a ‘socio-economic laboratory’ which allows to operate at levels of precision approaching those of the natural sciences.All data used in this study is fully anonymized; the authors have the written consent to publish from the legal department of the Medical University of Vienna.     

Public governance of information asymmetries—The gap between reality and economic theory

There are numerous situations where governments take action due to systematic information asymmetries in society, while economics textbooks do not offer an integrated theory to justify these interventions in terms of utility. This paper starts with a taxonomy of situations where governments try to correct for information asymmetries. A distinction is made between government interventions due to information asymmetries between market partners, within political markets and between the government and citizens. It is then shown that Public Choice Theory offers only few and Public Finance Theory not enough explanations for the prevalence of such government interventions. Further explanations for government actions are given by Institutional Economics and Cultural and Behavioural Economics. The latter will probably generate the best progress towards creating better explanations.     

An L1-type estimator of multivariate location and shape

The main goal of the paper is to specify a suitable multivariate multilevel model for polytomous responses with a non-ignorable missing data mechanism in order to determine the factors which influence the way of acquisition of the skills of the graduates and to evaluate the degree programmes on the basis of the adequacy of the skills they give to their graduates. The application is based on data gathered by a telephone survey conducted, about two years after the degree, on the graduates of year 2000 of the University of Florence. A multilevel multinomial logit model for the response of interest is fitted simultaneously with a multilevel logit model for the selection mechanism by means of maximum likelihood with adaptive Gaussian quadrature. In the application the multilevel structure has a crucial role, while selection bias results negligible. The analysis of the empirical Bayes residuals allows to detect some extreme degree programmes to be further inspected.     

Child Rights Practice among the Indigenous Communities in Bangladesh

The objective of this article was to explore the practice of child rights among the indigenous communities of Bangladesh. We used a mixed method approach to collect data from four ethnic communities in the Bandarban District of the Chittagong Division in Bangladesh. We questioned children, parents, community members, local leaders, and service providers of those communities on a number of child rights issues, for example, child education, child labor, child recreation and culture, parents' guidance to children for capacity development, and access to child rights at home and in the community according to Convention on the Rights of the Child treaty. The results showed that while the community was aware of child rights, financial vulnerability and a lack of social support meant that these rights could not be upheld in practice. The paper urges improvement of social support, including income generation activities for indigenous communities.     

Reforming against all odds: Multi‐pillar pension systems in the Czech Republic and Romania

Attempts to replace pay‐as‐you‐go pension schemes with private funded systems came to a halt in Central and Eastern Europe after 2005. However, more recently, the region has witnessed two belated reformers: the Czech Republic and Romania. Both countries decided to partially privatize pensions despite the rising tide of evidence concerning the challenges associated with the policy. We argue that while part of the domestic political elite remained supportive of private funded pensions, the difficulties experienced by earlier reformers and reduced support from International Financial Institutions led to the adoption of small funded pension pillars. Such cautious attempts at privatization might become more common in the future as large reforms have proven politically unsustainable.