"Download for Free" - When Do Providers of Digital Goods Offer Free Samples?

In a monopoly setting where consumers cannot observe the quality of the product we show that free samples which are of a lower quality than the marketed digital goods are used together with high prices as signals for a superior quality if the number of informed consumers is small and if the difference between the high and the low quality is not too small. Social welfare is higher, if the monopolist uses also free samples as signals, compared to a situation where he is restricted to pure price signalling. Both, the monopolist and consumers benefit from the additional signal

Influence of rearing environment on development of perching and dustbathing behaviour in laying hens

Studies have shown that perching and dustbathing behaviour in birds can be affected by how and when the behaviour develops. With the increasing trend away from cages and towards keeping laying hens in larger, more complex housing systems, it is important to improve our knowledge about what chicks need to learn if they are going to be able to fully use perches and litter when these are provided to them as adults. In the first part of this thesis the early use of perches and how this was influenced by the bird´s behaviour during the first weeks of life was investigated at the individual level. Furthermore the relationship between a bird’s spatial ability as a chick and as an adult was investigated by testing birds in two different two-dimensional spatial tests and by observing their use of perches. The aim was to investigate the degree to which birds are hatched with spatial skills or acquire these by using perches. The second part of the thesis dealt with the importance of access to an appropriate, that is to say, functional substrate for the development of dustbathing behaviour. Here comparisons of dustbathing behaviour by birds with different experiences of peat, a preferred dustbathing substrate, were carried out. In addition it was investigated whether birds that had only ever known sham dustbathing would be as motivated to get access to peat for dustbathing as birds reared and used to performing functional dustbathing. It was found that behaviour, such as spending more time underneath the perches, related positively with early perch use and the ability to solve a two dimensional spatial test was related to use of perches in a novel situation as adult. However, the results did not shed any light on whether chicks hatched with good spatial ability or if the spatial ability mostly developed through the use of perches. Dustbathing behaviour was influenced mainly by the substrate and the birds which gained or lost access to peat changed their dustbathing behaviour according to if they dustbathed in peat or on paper. Birds dustbathing on paper performed a less coherent dustbathing behaviour with more long and short bouts than birds dustbathing on peat. Irrespective of treatment all birds were motivated to get access to peat for dustbathing. These results imply that sham dustbathing can not replace functional dustbathing for a hen. In combination, the results of this thesis confirm the importance of giving early access to litter and perches also to the young chick

Ranking and Selecting Multi-Hop Knowledge Paths to Better Predict Human Needs

To make machines better understand sentiments, research needs to move from polarity identification to understanding the reasons that underlie the expression of sentiment. Categorizing the goals or needs of humans is one way to explain the expression of sentiment in text. Humans are good at understanding situations described in natural language and can easily connect them to the character's psychological needs using commonsense knowledge. We present a novel method to extract, rank, filter and select multi-hop relation paths from a commonsense knowledge resource to interpret the expression of sentiment in terms of their underlying human needs. We efficiently integrate the acquired knowledge paths in a neural model that interfaces context representations with knowledge using a gated attention mechanism. We assess the model's performance on a recently published dataset for categorizing human needs. Selectively integrating knowledge paths boosts performance and establishes a new state-of-the-art. Our model offers interpretability through the learned attention map over commonsense knowledge paths. Human evaluation highlights the relevance of the encoded knowledge

Automatic Accuracy Prediction for AMR Parsing

Abstract Meaning Representation (AMR) represents sentences as directed, acyclic and rooted graphs, aiming at capturing their meaning in a machine readable format. AMR parsing converts natural language sentences into such graphs. However, evaluating a parser on new data by means of comparison to manually created AMR graphs is very costly. Also, we would like to be able to detect parses of questionable quality, or preferring results of alternative systems by selecting the ones for which we can assess good quality. We propose AMR accuracy prediction as the task of predicting several metrics of correctness for an automatically generated AMR parse - in absence of the corresponding gold parse. We develop a neural end-to-end multi-output regression model and perform three case studies: firstly, we evaluate the model's capacity of predicting AMR parse accuracies and test whether it can reliably assign high scores to gold parses. Secondly, we perform parse selection based on predicted parse accuracies of candidate parses from alternative systems, with the aim of improving overall results. Finally, we predict system ranks for submissions from two AMR shared tasks on the basis of their predicted parse accuracy averages. All experiments are carried out across two different domains and show that our method is effective.Comment: accepted at *SEM 201

Crowding out or crowding in? Public and private transfers in Germany.

Intergenerational support regains attention in course of population aging. This paper focuses on the relationship between private and public financial transfers to and from the elderly. Based on German data we find that the giving of private transfers is influenced by public transfers. The close link between public transfers to the elderly and the financial support they give to others represents an inefficient backflow of pay-as-you-go financed pensions to the young generation. This mechanism can be interpreted as a private compensation device for the generations. We can also show that at the same time the receipt of public transfers by the elderly crowd-out private financial support they would have received otherwise in the German welfare state.

Retirement: Institutional Pathways and Individual Trajectories in Britain and Germany

Since the 1970s people have retired increasingly early across advanced societies. Parallel to this trend, numerous institutional early retirement pathways evolved, such as bridge unemployment and pre-retirement schemes. This article compares retirement in Britain and Germany to show how individuals progress through these institutional retirement pathways. The analysis uses longitudinal data and recent innovations in sequence analysis to capture the sequential nature of retirement as a series of transitions over time. As expected, prominent institutional retirement pathways are mirrored in individual retirement trajectories. Beyond these expected patterns, there are pronounced regularities in individual retirement trajectories outside of explicit institutional pathways. The \'institution of the family\' is an additional powerful force in structuring women\'s retirement. Access to advantageous institutional retirement pathways is stratified by gender, education, income, and health. The article concludes that specific population groups, particularly women, are systematically excluded from protective institutional early retirement pathways in Britain and Germany.Retirement, Aging, Life Course, Sequence Analysis, Germany, Britain, Gender

Labour market dynamics from a regional perspective : the multi-account system

"In the last years the analysis of flow figures turned out to highly informative for labour market research and policy advice. Among researchers it is a well known fact that cross-sectional information about labour market is not sufficient to understand ungoing development. A pure sequence of employment and unemployment figures would hide the turnover in the market. Here we follow the useful analytical framework of transitional labour markets dealing centrally with flow figures. By developing the multiaccount system (MAS) we go some steps ahead compared to indicators like job and labour turnover rates. First we combine the information of administrative data of the micro level with macro data containing pupils, self employed, retired persons. Embedded in an external framework, which is given by demography (birth, death, moving in and out), the MAS describes the transition process of the labour market on the regional level and contains all 180 local employment agencies in Germany. The multiaccount system thus serves as a basis for strategically aligning each agency with the individual local situation of the labour market by explicitly taking into account the regional specifics. Thus it helps for future strategic decisions of active labour market policy. The creation of models for supporting regional monitoring and benchmarking is already far advanced and initial basic versions are tested in practice. For estimating the unknown transitions of the data matrix we use a new algorithm the so called ADETON tool, which has the additional merit comparing to other entropy maximizing methods, that constraints can be formulated in a fuzzy way rather than exactly. Further we demonstrate on the basis of the agency Heilbronn some practice and numerical examples. Thus we present transitions into and out of unemployment and also from vocational training to employment. We believe that the analytical potential of this instrument is not yet exhausted. In any event, it is already clear that the information content of this model by far exceeds that of a system of individual indicators. Details and relations of the regional labour market become apparent which show a high-resolution image of possible obsolete structures or increasing labour market dynamics. The model thus gives clear hints as to the scope and limits of the active labour market policy." (Author's abstract, IAB-Doku) ((en))Arbeitskräftemobilität, labour turnover, job turnover, Berufsverlauf, Arbeitslosigkeit, Erwerbstätigkeit, arbeitsmarktpolitische Maßnahme, regionale Disparität

Restructuring Electricity Markets when Demand is Uncertain: Effects on Capacity Investments, Prices and Welfare

We examine the effects of restructuring electricity markets on capacity investments, retail prices and welfare when demand is uncertain. We study the following market configurations: (i) integrated monopoly, (ii) integrated duopoly with wholesale trade, and (iii) separated duopoly with wholesale trade. Assuming that wholesale prices can react to changes in retail prices (but not vice versa), we find that generators install sufficient capacity to serve retail demand in each market configuration, thus avoiding blackouts. Furthermore, aggregate capacity levels and retail prices are such that the separated (integrated) duopoly with wholesale trade performs best (worst) in terms of welfare.electricity; investments; generating capacities; vertical integration; monopoly and competition

Regional Unemployment and Job Switches in Germany – An Analysis at District Level

The role of mobility is central to the debate on reducing unemployment. A further question is to what extent a lack of mobility enforces regional disparities. Using a micro data set containing information about two cohorts we analyse the impact of regional unemployment at district level to regional employment duration. As an alternative to the frequently used Logit analysis approach we focus to duration time analyses. We use Cox Regression (Breslow Method for ties) and Piece wise constant models to find out the impact of regional unemployment rate for duration working in a special region. Additionally we could differentiate between voluntary and involuntary mobility. The results of this comparison show a contrary influence of the regional unemployment rate. Our results confirm the lower mobility of woman and that the younger cohort exhibits higher mobility rates. We also compare downward/upward moves (defined as wage losses/gains after mobility) and could not find evidence for influence of regional unemployment rate to wage growth. This yields us to the conclusion that high levels of regional unemployment inhibit mobility because of a lack of vacancies.