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Using a simulation design that is based on empirical data, a recent study by Huber et al. (J Econom 175:1–21, 2013) finds that distance-weighted radius matching with bias adjustment as proposed in Lechneret et al. (J Eur Econ Assoc 9:742–784, 2011) is competitive among a broad range of propensity score-based estimators used to correct for mean differences due to observable covariates. In this companion paper, we further investigate the finite sample behaviour of radius matching with respect to various tuning parameters. The results are intended to help the practitioner to choose suitable values of these parameters when using this method, which has been implemented in the software packages GAUSS, STATA and R.

This paper evaluates the effects of awarding vouchers for vocational training on the employment outcomes of unemployed voucher recipients in Germany, as well as the potential mechanism through which they operate. This study assesses the direct effects of voucher assignment net of actual redemption, which may be driven by preference shaping and learning about possible human capital investments or simply by the costs of information gathering. Using a formal mediation analysis framework based on sequential conditional independence assumptions and semiparametric matching estimators, our results suggest that the negative short-term and positive long-term em- ployment effects of receiving a voucher are mainly driven by actual training participation. However, the direct effect of just obtaining a voucher is negative over the short-run as well. This result points to potential losses in the effectiveness of such training provision systems if individuals decide not to redeem vouchers, as employment chances are lower than under non-award over the short-run and under redemption over the long-run, which makes non-redemption the least attractive option.

INTRODUCTION: Endoscopic anterior component separation (ECS) techniques facilitate tension-free midline closure of wide ventral hernia defects. We describe a novel approach with a precostal incision and a new cylindrical ballon trocar.MATERIALS AND METHODS: A single-center analysis of 19 patients undergoing ECS between January 1, 2014 and August 2, 2017 was performed with regard to improvement of technique. We currently start with a lateral precostal incision. This access in a low-fat and stable area allows for easy identification of the external oblique muscle with the ribs functioning as dorsal abutment for entering the correct plane between external and internal oblique muscles. Then a trocar is inserted with a cylindrical ballon, thus providing sufficient pneumatic widening of the dissection plane. A second 5-mm port is inserted under direct vision below the 12th rib. From there a unidirectional incision of the external oblique aponeurosis is performed from subcostal to the inguinal ligament. If necessary, the cephalad muscular parts of the external oblique can be transected over several centimeters in both directions starting from the precostal incision.RESULTS: We documented no procedure-related complications apart from two hematomas that required no interventions. Four procedures were carried out on one side and the remaining ones bilaterally. In one case, a conversion to conventional open component separation was required due to extensive scarring after open cholecystectomy. There were no notable abdominal bulgings or lateral hernias during a structured postoperative follow-up period of 1 year postoperatively.DISCUSSION: The technique described offers advantages in terms of determination of the correct entry point for ECS, regardless of abdominal wall conditions and the precostal access allows for unidirectional dissection toward the inguinal ligament with only two trocars in total. The cylindrical shape of the ballon trocar provides

This paper investigates the average effects of (firm-provided) workplace health promotion measures in form of the analysis of sickness absenteeism and health circles/courses on labour market out- comes of the firms’ employees. Exploiting linked employer-employee panel data that consist of rich survey- based and administrative information on firms, workers and regions, we apply a flexible propensity score matching approach that controls for selection on observables as well as on time- constant unobserved fac- tors. While the effects of analysing sickness absenteeism appear to be rather limited, our results suggest that health circles/courses increase tenure and decrease the number of job changes across various age groups. A key finding is that health circles/courses strengthen the labour force attachment of elderly em- ployees (51-60), implying potential cost savings for public transfer schemes such as unemployment or early retirement benefits.

During the last decade, many Western economies reformed their welfare systems with the aim of activating welfare recipients by increasing welfare-to-work programmes (WTWP) and job-search enforcement. We evaluate the short-term effects of three important German WTWP implemented after a major reform in January 2005 (‘Hartz IV’), namely short training, further training with a planned duration of up to three months and public workfare programmes (‘One-Euro-Jobs’). Our analysis is based on a combination of a large-scale survey and administrative data that is rich with respect to individual, household, agency level and regional information. We use this richness of the data to base the econometric evaluation on a selection-on-observables approach. We find that short-term training programmes, on average, increase their participants’ employment perspectives. There is also considerable effect heterogeneity across different subgroups of participants that could be exploited to improve the allocation of welfare recipients to the specific programmes and thus increase overall programme effectiveness.

Using exceptionally rich linked administrative and survey information on German welfare recipients we investigate the health effects of transitions from welfare to employment and of assignments to welfare-to-work programmes. Applying semi- parametric propensity score matching estimators we find that employment substantially increases (mental) health. The positive effects are mainly driven by males and individuals with bad initial health conditions and are largest for males with poor health. In contrast, the effects of welfare-to-work programmes, including subsidised jobs, are ambiguous and statistically insignificant for most outcomes. Copyright 2010 John Wiley & Sons, Ltd.

In this article, the authors assess the impact of firms’ offering a special form of phased retirement on their male employees’ labor market outcomes. The program aims at smoothing the transition from work to retirement and at decreasing costs in the public pension and unemployment insurance schemes through an increase in employment of elderly workers who otherwise would have exited prematurely through unemployment or early retirement. In line with these objectives, the authors assess whether male employees spend more time in employment and less time in unemployment or inactivity after the introduction of the program. The analysis is based on unique linked employer-employee data that combine high- quality survey and administrative data. Results suggest that phased retirement options offered by firms can help to reduce some of the public costs of low labor force attachment of elderly workers, mainly by reducing exits through unemployment and by increasing employment and earnings. Under relatively good labor market conditions, however, they may also encourage a small share of workers to exit the labor market earlier.

We investigate the finite sample properties of a large number of estimators for the average treatment effect on the treated that are suitable when adjustment for observed covariates is required, like inverse probability weighting, kernel and other variants of matching, as well as different parametric models. The simulation design used is based on real data usually employed for the evaluation of labour market programmes in Germany. We vary several dimensions of the design that are of practical importance, like sample size, the type of the outcome variable, and aspects of the selection process. We find that trimming individual observations with too much weight as well as the choice of tuning parameters are important for all estimators. A conclusion from our simulations is that a particular radius matching estimator combined with regression performs best overall, in particular when robustness to misspecifications of the propensity score and different types of outcome variables is considered an important property.

Previous research found that less accommodating caseworkers are more success- ful in placing unemployed workers into employment. This paper explores the causal mechanisms behind this result using semiparametric mediation analysis. Analysing rich linked jobseeker-caseworker data for Switzerland, we find that the positive employment effects of less accommodating caseworkers are not driven by a particularly effective mix of labour market programmes, but rather by other dimensions of the counselling process, possibly including threat effects of sanctions and pressure to accept jobs.

We investigate active labor market programs in Austria. We find only small effects, if any, for most of the programs. However, the programs may have unintended consequences for women. In particular for younger women, a key effect of the programs and one reason for the male-female effect differential that is observed in the literature is to reduce or postpone pregnancies and to increase their attachment to the labor force. Furthermore, the variables capturing pregnancies and times of parental leave play a key role in removing selection bias

This paper approaches the dynamic analysis of the effects of training programs for the unemployed in West Germany, or in general the effects of sequences of interventions, from a potential outcome perspective. The identifying power of different assumptions concerning the connection between the dynamic selection process and the outcomes of different sequences is discussed. When participation in the particular sequence of programs is decided period by period depending on its success so far, many parameters of interest are no longer identified. Nevertheless, some interesting dynamic forms of the average treatment effect are identified by a sequential randomization assumption. Based on this approach, we present some new results on the effectiveness of West-German training programs