THE CAUSAL LINK BETWEEN FINANCIAL INCENTIVES AND WEIGHT LOSS: AN EVIDENCE‐BASED SURVEY OF THE LITERATURE

Obesity and overweight are linked to diseases that cost society a significant amount of resources. While behavior modification can reduce the problem, instigating such lifestyle changes is an uneasy task. One potential way to reduce the problem is through the use of financial incentives. In this survey, we review the available evidence, properly emphasizing studies that credibly yield meaningful estimates of the effect of financial incentives on weight loss. We find that the scientific literature on the subject has not yet satisfactorily settled whether such a mechanism is effective at eliciting the desired behavioral and health outcomes. We therefore advocate a rigorous large‐scale randomized experiment to provide reliable estimates of the effect.     

The transformation of the German vocational training regime: evidence from firms’ training behaviour

The German system of industrial relations has undergone significant changes in the last decade. This article reflects on and provides empirical evidence for how these changes have affected the training behaviour of firms. Conventional perspectives would predict a general decline in training investment when the constraints of collective wage bargaining are loosened. Relying on a large data set on the costs and benefits of apprenticeship training for the years 2000 and 2007, we do find evidence for this hypothesis but would add that the strength of the effect varies strongly across different types of firms. Large firms have benefited much more from participating in training than have small firms and have therefore maintained their investment in training because they are able to reduce net costs by expanding the productive contributions of apprentices. This finding may help to explain the apparent resilience of the German training system in the recent economic and financial crisis.     

Imitation,Contagion, or Exertion? Using a Tax Reform to Reveal How Colleagues' Sick Leaves Influence Worker Behaviour

We analyse the social interaction effects in sick‐leave behaviour in the workplace, using high‐quality Norwegian matched employer–employee data with detailed individual information on sick leaves during the 2004–2006 period. We find that social interaction effects in sick‐leave behaviour in the workplace do exist, and that the effects are noticeable in size. The strong relationship between the sick‐leave rates among colleagues is not solely the result of contagious diseases, nor is it caused by improved informational quality or by the increased workload for the non‐absent workers. Evidence supports the existence of reciprocal worker behaviour that is unrelated to joint leisure‐seeking activities.     

Does Export Openness Increase Firm‐level Output Volatility?

There is a widespread concern that increased trade may lead to increased instability and thus risk at the firm level. Greater export openness can indeed affect firm‐level volatility by changing the exposure and the reaction of firms to macroeconomic developments. The net effect is ambiguous from a theoretical point of view. This paper provides firm‐level evidence on the link between openness and volatility. Using comprehensive data on more than 21,000 German manufacturing firms for the period 1980–2001, we analyse the evolution of firm‐level output volatility and the link between volatility and export openness. Our paper has three main findings. First, firm‐level output volatility is significantly higher than the level of aggregate volatility, but it displays similar patterns. Second, increased export openness lowers firm‐level output volatility. This effect is primarily driven by variations along the extensive margin, i.e. by the distinction between exporters and non‐exporters. Variations along the intensive margin, i.e. the volume of exports, tend to have a dampening impact on volatility as well. Third, small firms are more volatile than large firms.     

Choice is suffering: A Focused Information Criterion for model selection

In contrast to conventional measures, the Focused Information Criterion (FIC) allows the purpose-specific selection of models, thereby reflecting the idea that one kind of model might be appropriate for inferences on a parameter of interest, but not for another. Ever since its invention, the FIC has been increasingly applied in the realm of statistics, but this concept appears to be virtually unknown in the economic literature. Using a straightforward analytical example, this paper provides for a didactic illustration of the FIC and demonstrates its usefulness in economic applications.     

On the composition of elementary errors

Analysis of statistical distributions.

1. Let m and σ denote the mean and the standard deviation of a statistical variable X, and let W(x) be the probability function of that variable as defined in the first paper ¹ This journal, 1928, p. 13. We shall refer to that paper by the letter I. — The sense in which the words probability function and frequency function are used here must be carefully observed, If the probability that a certain variable lies between x and x+dx is f(x) dx, then f(x) is the frequency function of the variable. The probability function is, in cases where a finite frequency function ex-ists, equal to the integral of the latter, taken over the interval from -∞ to x — The notations of the present paper will, as a rule, correspond to those of I, the most important exception being the symbol n , which will here always denote the number of observations in a statistical series and not, as in I, the number of elementary components. , Art. 1. If we put (cf. I, formula (3)) F(x) is the probability function of the variable , with the mean value 0 and the standard deviation 1. Denoting by µ₂, µ₃, ... the moments of W(x) , taken about the mean (cf. I, Art. 7, where m is supposed to be zero), we put, following Charlier,      

Maximum diversification strategies along commodity risk factors

Pursuing risk‐based allocation across a universe of commodity assets, we find diversified risk parity (DRP) strategies to provide convincing results. DRP strives for maximum diversification along uncorrelated risk sources. A straightforward way to derive uncorrelated risk sources relies on principal components analysis (PCA). While the ensuing statistical factors can be associated with commodity sector bets, the corresponding DRP strategy entails excessive turnover because of the instability of the PCA factors. We suggest an alternative design of the DRP strategy relative to common commodity risk factors that implicitly allows for a uniform exposure to commodity risk premia.