Why don’t they answer? Unit non-response in the IAB establishment panel

The paper proposed focuses on the unit-nonresponse in the IAB (Institute for Employment Research) Establishment Panel, a comprehensive data set describing the employer side of the labour market in Germany. Every year since 1993 (1996) the IAB Establishment Panel has surveyed the same establishments from all branches and different size categories in western (eastern) Germany. Although great efforts are taken to convince the owner/manager to take part in the survey there are always firms that do not answer the questionnaire. In this paper the authors try to find out why some establishments are not willing or able to respond to the questionnaire. If the respondent has the authority to provide relevant information, is able to give reliable answers to the questions with a justifiable amount of effort and is interested in the survey in business terms, participation is less frequently refused. The results also confirm the central significance of the interaction between the respondent and the interviewer. If one of the two individuals changes, the probability of further participation falls clearly.     

Die Macht der Meinungsmacher: Ratingagenturen und staatliche Verschuldungsdynamiken

Die Finanzm?rkte reagieren in der gegenw?rtigen Staatsschuldenkrise offensichtlich auf Meinungs?u?erungen der marktbeherrschenden Ratingagenturen — selbst wenn diese in scheinbarem Widerspruch zur vorherigen Bewertung ?konomischer Fundamentaldaten stehen. Das führt dazu, dass private Interessen staatliche Verschuldungsdynamiken beeinfl ussen k?nnen und für sie damit politischer Handlungsspielraum entsteht.     

Local volatility under rough volatility

Several asymptotic results for the implied volatility generated by a rough volatility model have been obtained in recent years (notably in the small-maturity regime), providing a better understanding of the shapes of the volatility surface induced by rough volatility models, supporting their calibration power to SP500 option data. Rough volatility models also generate a local volatility surface, via the so-called Markovian projection of the stochastic volatility. We complement the existing results on implied volatility by studying the asymptotic behavior of the local volatility surface generated by a class of rough stochastic volatility models, encompassing the rough Bergomi model. Notably, we observe that the celebrated “1/2 skew rule” linking the short-term at-the-money skew of the implied volatility to the short-term at-the-money skew of the local volatility, a consequence of the celebrated “harmonic mean formula” of [Berestycki et al. (2002). Quantitative Finance, 2, 61–69], is replaced by a new rule: the ratio of the at-the-money implied and local volatility skews tends to the constant $1/(H+3/2)$ (as opposed to the constant 1/2), where H is the regularity index of the underlying instantaneous volatility process.