On the formulation of uniform laws of large numbers: a truncation approach

The paper develops a general framework for the formulation of generic uniform laws of large numbers. In particular, we introduce a basic generic uniform law of large numbers that contains recent uniform laws of large numbers by Andrews [2] and Hoadley [9] as special cases. We also develop a truncation approach that makes it possible to obtain uniform laws of large numbers for the functions under consideration from uniform laws of large numbers for truncated versions of those functions. The point of the truncation approach is that uniform laws of large numbers for the truncated versions are typically easier to obtain. By combining the basic uniform law of large numbers and the truncation approach we also derive generalizations of recent uniform laws of large numbers introduced in Pötscher and Prucha [15, 16].     

The development of gaze following in monolingual and bilingual infants: A multi-laboratory study

Determining the meanings of words requires language learners to attend to what other people say. However, it behooves a young language learner to simultaneously encode relevant non-verbal cues, for example, by following the direction of their eye gaze. Sensitivity to cues such as eye gaze might be particularly important for bilingual infants, as they encounter less consistency between words and objects than monolingual infants, and do not always have access to the same word-learning heuristics (e.g., mutual exclusivity). In a preregistered study, we tested the hypothesis that bilingual experience would lead to a more pronounced ability to follow another's gaze. We used a gaze-following paradigm developed by Senju and Csibra (Current Biology, 18, 2008, 668) to test a total of 93 6- to 9-month-old and 229 12- to 15-month-old monolingual and bilingual infants, in 11 laboratories located in 8 countries. Monolingual and bilingual infants showed similar gaze-following abilities, and both groups showed age-related improvements in speed, accuracy, frequency, and duration of fixations to congruent objects. Unexpectedly, bilinguals tended to make more frequent fixations to on-screen objects, whether or not they were cued by the actor. These results suggest that gaze sensitivity is a fundamental aspect of development that is robust to variation in language exposure.     

Determinanten der Vorstandsvergütung

Using a novel, hand-collected data set covering all German non-financial firms listed in the Prime Standard of FWB (Frankfurt Stock Exchange), we examine determinants of executive compensation in German listed firms. We distinguish three potential determinants: firm characteristics, firm performance, and corporate governance characteristics. While we find that simple firm characteristics like size and industry affiliation together with time effects explain more than 60 % of variation in overall compensation, performance characteristics are economically inconsequential for the explanation of compensation levels. When we distinguish between widely held firms and firms with a large blockholder, we find that the latter grant compensation packages that are smaller, less sensitive to the firm’s stock market performance but more sensitive to the firm’s operating performance. Finally, we confirm that supervisory board characteristics also affect the level of executive compensation in German firms. Overall, our findings suggest that although the corporate governance environment in Germany has changed dramatically during the last decade, German listed firms are still exposed to high agency costs.     

Considering the shareholder perspective: value-based management systems and stock market performance

We empirically study the use of value-based management systems in listed German firms and examine implications for firms’ stock market performance. Using a novel, hand-collected data set covering 1,083 firm years from 2002 to 2008, we find that value-based management systems become increasingly common. Specifically, in 2008 42% of our sample firms have implemented such a system. In the empirical analysis, we find that firms implementing value-based management systems earn both statistically significant and economically substantial abnormal stock market returns measured within a 2-year adoption phase. These excess returns are not jeopardized by poor post-adoption returns. In the analysis, we carefully control for risk and account for endogeneity concerns. Overall, our findings support the view that shareholders consider the adoption of a value-based management system as a credible signal that management will focus on shareholder interests and that such systems actually increase shareholder value.     

Basic structure of the asymptotic theory in dynamic nonlinear econometric models

This is the second of two papers that provide an expository discussion of the basic structure of the asymptotic theory of M-estimators in dynamic nonlinear models and a review of the literature. The first paper, Pötscher and Prucha(1991), deals with consistency. In the present paper we discuss asymptotic normality. As an important ingredient to the asymptotic normality proof in dynamic nonlinear models we consider central limit theorems for dependent random variables. We also discuss the estimation of the variance covariance matrix of m-estimators under heteroscedasticity and autocorrelation.     

Basic structure of the asymptotic theory in dynamic nonlineaerco nometric models,part i: consistency and approximation concepts

This is the first of two papers that provide an expository discussion of the basic structure of the asymptotic theory of M-estimators in dynamic nonlinear models and a revlew of the literature. In this paper we discuss consistency,uniform laws of large numbers and develop a new framework for laws of large numbers for dependent and heterogeneous processes, encompassing the theory of stochastically stable as well as near epoch dependent processes. This framework results in simplified catalogues of sufficient conditions for consistency. The second paper, Potscher and Prucha (1990b), deals with asymptotic distribution theory.     

Prospective analysis of time out-of-home and objectively measured walking duration during a week in a large cohort of older adults

Background

Physical activity is considered an effective measure to promote health in older people. There is evidence that the number of outdoor trips increases physical activity by increasing walking duration. The objective of this study was to analyse the relationship between daily time out-of-home and walking duration. Furthermore, predictors for walking duration and time out-of-home were evaluated.

Methods

Walking duration was measured prospectively over a 1 week period by a body-fixed sensor and the time out-of-home was assessed by a questionnaire at the same days. Seven thousand, two hundred and forty-three days from 1289 older people (mean age 75.4 years) with both sensor-based measures and completed questionnaires were included in the analyses. To account for several observation days per participant multilevel regression analyses were applied. Analyses were stratified according to the time out-of-home (more or less than 100 min/day).

Results

In the group with less than 100 min out-of-home, each additional minute out-of-home added 20 s to overall walking duration. If the time exceeded 100 min the additional increase of walking duration was only moderate or weak. Leaving the home once added 40 min of walking, the following trips 15 to 20 min. Increasing age, lower gait speed, comorbidities, low temperature, rain and specific week days (Sunday) decreased both the time out-of-home and walking duration. Other variables like gender (female), isolation or living with a spouse reduced the time out-of-home without affecting walking duration.

Conclusions

Being out-of-home increases daily walking duration. The association is strongest if the time out-of-home is 100 min or less.

     

Basic structure of the asymptotic theory in dynamic nonlineaerco nometric models, part i: consistency and approximation concepts

This is the first of two papers that provide an expository discussion of the basic structure of the asymptotic theory of M-estimators in dynamic nonlinear models and a revlew of the literature. In this paper we discuss consistency,uniform laws of large numbers and develop a new framework for laws of large numbers for dependent and heterogeneous processes, encompassing the theory of stochastically stable as well as near epoch dependent processes. This framework results in simplified catalogues of sufficient conditions for consistency. The second paper, Potscher and Prucha (1990b), deals with asymptotic distribution theory.