University of Mannheim

About: University of Mannheim is a education organization based out in Mannheim, Germany. It is known for research contribution in the topics: Context (language use) & Politics. The organization has 4448 authors who have published 12918 publications receiving 446557 citations. The organization is also known as: Uni Mannheim & UMA.

From zero to hero: On the limitations of zero-shot language transfer with multilingual transformers

Abstract: Massively multilingual transformers (MMTs) pretrained via language modeling (e.g., mBERT, XLM-R) have become a default paradigm for zero-shot language transfer in NLP, offering unmatched transfer performance. Current evaluations, however, verify their efficacy in transfers (a) to languages with sufficiently large pretraining corpora, and (b) between close languages. In this work, we analyze the limitations of downstream language transfer with MMTs, showing that, much like cross-lingual word embeddings, they are substantially less effective in resource-lean scenarios and for distant languages. Our experiments, encompassing three lower-level tasks (POS tagging, dependency parsing, NER) and two high-level tasks (NLI, QA), empirically correlate transfer performance with linguistic proximity between source and target languages, but also with the size of target language corpora used in MMT pretraining. Most importantly, we demonstrate that the inexpensive few-shot transfer (i.e., additional fine-tuning on a few target-language instances) is surprisingly effective across the board, warranting more research efforts reaching beyond the limiting zero-shot conditions.

Principal-agent problems in international organizations

Abstract: The paper provides a framework for analysing control problems in international organisations and reviews the disparate evidence from a public-choice perspective. Most examples concern the European Union, the International Monetary Fund, the World Bank and the International Labour Organisation. International organisations suffer from principal-agent problems more than other public or private organisations do because the chain of delegation is more extended. As survey evidence demonstrates, the actors in international organisations do not share the preferences of the citizens because they have vested interests, and the citizens believe that they have least influence at the international level. The paper argues that national and international parliaments, the national governments and international supervisory boards or courts cannot solve the principal-agent problem due to severe information cost and weak or distorted incentives.

Modified DFT filter banks with perfect reconstruction

Abstract: In this paper, essential features of the recently introduced modified discrete Fourier transform DFT (MDFT) filter bank are presented. First, it is shown that all analysis and synthesis filters-obtained by appropriate complex modulation of a low-pass prototype filter-are linear phase. This is important for subband image coding applications. Another important property is the structure-inherent alias cancellation: all odd alias spectra are automatically compensated in the synthesis filter bank. Further, the MDFT filter bank provides perfect reconstruction for the same prototypes as for cosine-modulated filter banks. Thus, the same design methods can be used. Finally, different mappings of the input signal into the subbands are discussed and a comparison to the well-known cosine-modulated filter banks is given.

Bildungsungleichheit im Sozialen Wandel

Abstract: Im Unterschied zu der in der Literatur weithin verbreiteten These konstanter Ungleichheiten zeigt dieser Beitrag, das seit der Zwischenkriegszeit und den ersten Nachkriegsjahren die Unterschiede zwischen verschiedenen Bevolkerungsgruppen in der Bildungsbeteiligung und in den erworbenen Bildungsabschlussen deutlich kleiner geworden sind. Die Analyse sukzessiver Ubergange zwischen den verschiedenen Stufen des Bildungswesens belegt, das die Ungleichheit insbesondere durch einen Abbau der sozialen Beteiligungsdifferentiale beim Ubergang zu den weiterfuhrenden Schulen und beim Erwerb der Mittleren Reife geringer geworden ist. Als Folge haben aber auch die Ungleichheiten beim Erwerb des Abiturs und von Hochschulabschlussen abgenommen. Die Ungleichheitsreduktion ist unterschiedlich stark nach unterschiedlichen Ungleichheitsdimensionen und sie variiert in unterschiedlichen Phasen der Nachkriegsentwicklung. Aus der Konstellation der Befunde werden spezifische Hypothesen zur Erklarung des Ungleichheitsabbaus diskutiert.

Why Groups are less Effective than their Members: On Productivity Losses in Idea-generating Groups

Abstract: There is pervasive evidence that people produce more ideas and more good ideas when working alone rather than in groups. This chapter will first review the evidence for the productivity loss in brainstorming groups and then evaluate the various theoretical explanations which have been offered to account for these findings in the light of empirical research. This evidence suggests that the productivity loss in idea-generating groups is caused mainly by mutual production blocking due to the constraint on groups that members can talk only in turn. We then discuss various strategies that have been developed to overcome the disruptive effects of production blocking. However, since so far even the most successful strategies have raised the productivity of group members only to the level they would have achieved if they had worked individually, our final section discusses an ‘illusion of group effectivity’ as a reason for the persistence of the belief that group discussions are an effective means of generating i...