30394 research outputs found
Sort by
The Stick-Breaking and Ordering Representation of Compositional Data: Copulas and Regression models
Get PDFCompositional Data (CoDa) is usually viewed as data on the simplex and is studied via a log-ratio analysis, following the classical work of Aitchison [2]. We propose to bring to the fore an alternative view of CoDa as a stick breaking process, an approach which originates from Bayesian nonparametrics. The first stick-breaking approach gives rise to a view of CoDa as ordered statistics, from which we can derive “stick-ordered” distributions. The second approach is based on a rescaled stick-breaking transformation, and give rises to a geometric view of CoDa as a free unit cube. The latter allows to introduce copula and regression models, which are useful for studying the internal or external dependence of CoDa. These stick-breaking representations allow to effectively and simply deal with CoDa with zeroes. We establish connections with other topics of probability and statistics like i) spacings and order statistics, ii) Bayesian nonparametrics and Dirichlet distributions, iii) neutrality, iv) hazard rates and the product integral, v) mixability
Motivating Public Sector Employees: Public Good Contributions in Addis Ababa Water and Sewerage Authority
Get PDFWe present a lab-in-the-field experiment with employees of the Addis Ababa Water and Sewerage Authority to understand how to improve coordination and collaboration in their daily work. Participants play a series of public good games under different rules: a standard game, a game with a threshold, and a game with a randomly selected anonymous monitor who has the power to punish. We show that a common goal, in the form of a threshold to be attained for the group’s success, is significantly more effective than a potentially punishing monitor for increasing individual effort and, ultimately, group outcomes (conditional on the threshold being attained). This result advocates for the introduction of team goals as coordination and motivation devices in settings where tasks are performed by groups and are subject to free riding and coordination challenges
Dyadic isolation in social interactions : the role of depressive symptoms
No full textDyadic isolation is the tendency of some individuals to be involved in pairwise interactions rather than in larger group interactions. This article investigates the interpersonal processes associated with the dyadic isolation of individuals with depressive symptoms. We hypothesize that such individuals tend to initiate more and stay longer in dyadic interactions compared to group interactions (dyadic preference hypothesis) and that individuals—irrespective of their own level of depressive symptoms—tend to join and stay longer in interactions when interaction partners have lower levels of depressive symptoms (depression avoidance hypothesis). We analyze two data sets (N = 123) of face-to-face interaction events (N = 86,915) collected with proximity badges at a social event. Hypotheses are tested using a relational event model (DyNAM-i) specifically tailored for modeling group interactions. In line with the dyadic preference hypotheses, individuals with higher levels of depressive symptoms are found to be more likely to join and stay in dyadic interactions. Post hoc analyses reveal that this result only applies to female participants. We find limited support for the depression avoidance hypotheses
Third-degree price discrimination in two-sided markets
No full textWe investigate the welfare effects of third-degree price discrimination by a two-sided platform that enables interaction between buyers and sellers. Sellers are heterogeneous with respect to their per-interaction benefit, and, under price discrimination, the platform can condition its fee on sellers’ type. In a model with linear demand on each side, we show that price discrimination (i) increases participation on both sides, (ii) enhances total welfare, and (iii) may result in a strict Pareto improvement, with both seller types being better off than under uniform pricing. These results, which are in stark contrast to the traditional analysis of price discrimination, are driven by the existence of cross-group network effects. By improving the ability to monetize seller participation, price discrimination induces the platform to attract more buyers, which then increases seller participation. The Pareto improvement result means that even those sellers who pay a higher price under discrimination can be better off, because of the increased buyer participation
Too Domestic to Fail: Liquidity Provision and National Champions
No full textAuthorities’ support policies shape the location and continuation of industrial and banking activity on their soil. Firms’ locus of activity depends on their prospect of receiving financial assistance in distress and therefore on factors such as countries’ relative resilience. We predict that global firms are global in life and national in death; and that they become less global when competition is more intense, times are turbulent, and international risk sharing (say, through swap lines) weak. We analyse the competitive benefits of industrial and banking policies as well as their limitations, such as currency appreciation
Social learning preserves both useful and useless theories by canalizing learners’ exploration
Get PDFIn many domains, learning from others is crucial for leveraging cumulative cultural knowledge, which encapsulates the efforts of successive generations of innovators. However, anecdotal and experimental evidence suggests that reliance on social information can reduce the exploration of the problem space. Here, we experimentally investigate the extent to which cultural transmission fosters the persistence of arbitrary solutions in a context where participants are incentivized to improve a physical system across multiple trials. Participants were exposed to various theories about the system, ranging from accurate to misleading. Our findings indicate that even under conditions conducive to exploration, the transmission of cultural knowledge canalizes learners’ focus, limiting their consideration of alternative solutions. This effect was observed in both the theories produced and the solutions attempted by participants, irrespective of the accuracy of the provided theories. These results challenge the notion that arbitrary solutions persist only when they are efficient or intuitive and underscore the significant role of cultural transmission in shaping human knowledge and technologies
From Doctrine to Data: Towards an Empirical Turn in European Legal Scholarship?
No full textEmpirical Legal Research (ELR) can be defined as the systematic collec-tion and analysis of data on legal phenomenon, in a way that is verifia-ble, reproducible and falsifiable. Europe is a good case to study the de-velopment of ELR, notably given the long tradition of unity in legal scholarship. Of course, this tradition is that of doctrinal scholarship but, at the turn of the 20th century, it was partially challenged by the emer-gence of new social sciences. Nowadays, ELR implicitly challenges the division of labour that resulted from this period, by using social science methods to grasp legal objects. It thus challenges normativist dogma and goes beyond legal realism. If there were any doubt about that, ELR can be considered “legal” research, notably because, at least in some cases, its object is purely legal. However, this does not mean that ELR answers the same questions as doctrinal approaches. Although ELR seems to be developing in Europe, some countries are lagging behind, for example France where interest in ELR has only been growing in re-cent years. At the European level, signs of growth are more tangible. This raises questions regarding the structuring of this field of research. This special issue aims to answer them
