P(enalized)-splines and fractional polynomials (FPs) have emerged as powerful smoothing techniques with increasing popularity in applied research. Both approaches provide considerable flexibility, but only limited comparative evaluations of the performance and properties of the two methods have...

In recent years, considerable research has been devoted to developing complex regression models that can deal simultaneously with nonlinear covariate effects and time trends, unit- or cluster specific heterogeneity, spatial heterogeneity and complex interactions between covariates of different...

"For micro-datasets considered for release as scientific or public use files, statistical agencies have to face the dilemma of guaranteeing the confidentiality of survey respondents on the one hand and offering sufficiently detailed data on the other hand. For that reason a variety of methods to...

"Influential studies have suggested that initial conditions can have persistent effects on workers' careers within firms. It is a longstanding question among economists whether such lasting wage differentials among firms and industries are due to persistent deviations of wages from workers'...

"We analyze the wage effects of employment breaks of women entering motherhood using a novel within-firm matching approach where mothers' wages upon return to the job are compared with those of their female colleagues within the same firm. Using an administrative German data set we investigate...

"We show that workers displaced from their stable jobs during mass-layoffs in 1982 recession in Germany suffered permanent earnings losses of 10-15% lasting at least 15 years. These estimates are obtained using data and methodology comparable to similar studies for the United States. Exploiting...