Is there a Superior Distance Function for Matching in Small Samples?
Eva Dettmann, Claudia Becker, Christian Schmeißer
Abstract
The study contributes to the development of ’standards’ for the application of matching algorithms in empirical evaluation studies. The focus is on the first step of the matching procedure, the choice of an appropriate distance function. Supplementary o most former studies, the simulation is strongly based on empirical evaluation ituations. This reality orientation induces the focus on small samples. Furthermore, ariables with different scale levels must be considered explicitly in the matching rocess. The choice of the analysed distance functions is determined by the results of former theoretical studies and recommendations in the empirical literature. Thus, in the simulation, two balancing scores (the propensity score and the index score) and the Mahalanobis distance are considered. Additionally, aggregated statistical distance functions not yet used for empirical evaluation are included. The matching outcomes are compared using non-parametrical scale-specific tests for identical distributions of the characteristics in the treatment and the control groups. The simulation results show that, in small samples, aggregated statistical distance functions are the better
choice for summarising similarities in differently scaled variables compared to the
commonly used measures.
Read article
Subsidized Vocational Training: Stepping Stone or Trap? An Evaluation Study for East Germany
Eva Dettmann, Jutta Günther
IWH Discussion Papers,
No. 21,
2009
Abstract
The aim of this paper is to analyze whether the formally equal qualifications acquired during a subsidized vocational education induce equal employment opportunities compared to regular vocational training. Using replacement matching on the basis of a statistical distance function, we are able to control for selection effects resulting from different personal and profession-related characteristics, and thus, to identify an unbiased effect of the public support. Besides the ‘total effect’ of support, it is of special interest if the effect is stronger for subsidized youths in external training compared to persons in workplace-related training. The analysis is based on unique and very detailed data, the Youth Panel of the Halle Centre for Social Research (zsh).
The results show that young people who successfully completed a subsidized vocational education are disadvantaged regarding their employment opportunities even when controlling for personal and profession-related influences on the employment prospects. Besides a quantitative effect, the analysis shows that the graduates of subsidized training work in slightly worse (underqualified) and worse paid jobs than the adolescents in the reference group. The comparison of both types of subsidized vocational training, however, does not confirm the expected stronger effect for youths in external vocational education compared to workplace-related training.
Read article
Warum exportiert der Osten so wenig? Eine empirische Analyse der Exportaktivitäten deutscher Bundesländer
Götz Zeddies
AStA - Wirtschafts- und Sozialstatistisches Archiv,
No. 4,
2009
Abstract
In the aftermath of re-unification, East German exports declined around 70% due to the breakdown of COMECON trade. Although since the mid-1990s export growth rates of the New Federal States were higher than those of their West German counterparts, export performance of East German States measured by the share of exports in GDP is still comparatively poor. Whereas for a long time the low export performance of East German producers was ascribed to competitive disadvantages, in the meantime structural deficits on the micro and/or macro level are often considered as the main reason. Using bilateral trade data of German Federal States, the present paper shows on the basis of an orthodox gravity model of trade that East German exports are explicitly lower than predicted by the model. But if the gravity model is augmented by additional variables representing structural differences between Federal States, the latter explain almost entirely the lower export performance of Eastern Germany. Thus, especially the smaller firm sizes and the lower shares of manufacturing industries in gross value added are identified as important explanatory factors of the comparatively weak export performance of the New German States.
Read article
A Panel Data Analysis on China's Intra-Industry Trade in the Capital Goods Sector
Yiping Zhu
IWH Discussion Papers,
No. 18,
2009
Abstract
This paper adopts the Hausman-Taylor 2SLS error components approach in estimating the determinants of China's Intra-Industry Trade (IIT) in the capital goods sector with its 26 partner countries. It disaggregates IIT into horizontal IIT (HIIT) and vertical IIT (VIIT). Capital goods final products and intermediates are separately estimated in order to reveal the differentiated trade patterns. It finds that economic similarity is very significantly negatively correlated with the intermediates IIT, but to a less extent correlated with the final products IIT. Factor endowment is of no significance in determining IIT in the intermediates, although it is significantly positively correlated with the final products IIT. Economic size is significantly negatively correlated with both final products and intermediates IIT. Distance is not yet dead in impacting the level of final products IIT, but of less importance in influencing the intermediates IIT. China is exchanging intermediates in a less intraindustry manner with ASEAN nations. However, because VIIT is dominating TIIT, no significant differences exist between the estimation results of TIIT and VIIT.
Read article
The Identification of Regional Industrial Clusters Using Qualitative Input-Output Analysis
Mirko Titze, Matthias Brachert, Alexander Kubis
IWH Discussion Papers,
No. 13,
2008
Abstract
The ‘cluster theory’ has become one of the main concepts promoting regional competitiveness, innovation, and growth. As most studies focus on measures of concentration of one industrial branch in order to identify regional clusters, the appropriate analysis of specific vertical relations within a value-adding chain is developing in this discussion. This paper tries to identify interrelated sectors via national input-output tables with the help of Minimal Flow Analysis by Schnabl (1994). The regionalization of these national industry templates is carried out with the allocation of branch-specific production values on regional employment. As a result, the paper shows concentrations of vertical clusters in only 27 of 439 German NUTS-3 regions.
Read article
Three methods of forecasting currency crises: Which made the run in signaling the South African currency crisis of June 2006?
Tobias Knedlik, Rolf Scheufele
IWH Discussion Papers,
No. 17,
2007
Abstract
In this paper we test the ability of three of the most popular methods to forecast the South African currency crisis of June 2006. In particular we are interested in the out-ofsample performance of these methods. Thus, we choose the latest crisis to conduct an out-of-sample experiment. In sum, the signals approach was not able to forecast the outof- sample crisis of correctly; the probit approach was able to predict the crisis but just with models, that were based on raw data. Employing a Markov-regime-switching approach also allows to predict the out-of-sample crisis. The answer to the question of which method made the run in forecasting the June 2006 currency crisis is: the Markovswitching approach, since it called most of the pre-crisis periods correctly. However, the “victory” is not straightforward. In-sample, the probit models perform remarkably well and it is also able to detect, at least to some extent, out-of-sample currency crises before their occurrence. It can, therefore, not be recommended to focus on one approach only when evaluating the risk for currency crises.
Read article
Vergleich der Weiterbildungsaktivitäten von Arbeitslosen und Vollzeiterwerbstätigen
Birgit Schultz, Joachim Wilde
IWH Discussion Papers,
No. 9,
2007
Abstract
Many empirical studies consider either training activities of the unemployed or training activities of the employees in Germany. However, a comprehensive comparison of both groups is missing. The paper closes this gap. Using data of the latest time use survey (Zeitbudgeterhebung) of the Federal Statistical Office, the amount of training is compared for both groups. Furthermore, it is described which types of activities are made use of in particular. Heterogeneity due to different relevant socioeconomic characteristics in the two groups is eliminated by the appliance of a matching procedure. Findings demonstrate that only 49% of the unemployed persons participate in any kind of training activities off the job. In case of the full-time employment 59 % would take part. Concerning the average expenditure of time per week the difference turns around, i.e. the expenditure of time is higher during unemployment. However, a high proportion of the training activities of the unemployed falls upon general training, e.g. by reading books or watching TV. Furthermore, the result is driven by a different potential of time that can be used for training activities off the job. Relating to this potential of time the amount of training activities is still lower during unemployment.
Read article
Microeconometric Evaluation of Selected ESF-funded ALMP-Programmes
Eva Reinowski, Birgit Schultz
IWH Discussion Papers,
No. 17,
2006
Abstract
The study evaluates different ESF-funded labour market programmes by comparing the labour market status at different points in time after the treatment. In order to solve the selection problem we employ a standard matching algorithm with a multi-dimensional distance measure. The effects of the analyzed programmes (wage subsidies, start-up subsidies and qualification measures for recipients of social welfare) are very heterogeneous. It can be observed that the direct integration into the regular labour market provides an advantage for the supported individuals. Its lasting effects, however, strongly depend on the group of persons being supported, the type of treatment and the employers’ financial share.
Read article
Options and Limits of the Matching Approach – An Application to Workers Participation
Birgit Schultz
IWH Discussion Papers,
No. 15,
2006
Abstract
The evaluation of economic effects of workers participation is not simple from the methodical point of view because of specific characteristics of establishments with works councils. Especially recent studies show contradictory results. In this study problems are pointed out, discussed, and options for solution are presented on the example of workers participation in East German establishments of industry and construction by the IABEstablishment Panel. An optimal matching-algorithm which supplies good matching-results for small samples to assign ‘statistical establishment-twins’ is applied. But by reason of very short primarily spells it can only calculate short time effects. Therefore, the matching method is additionally used to construct longer observation periods. By this new application establishments with recently founded works councils are matched with so called ‘proxy establishments’ with existing works councils. As a result short observation periods are prolonged and information about long-term effects can be given. The effects on productivity, profitability and qualification level of employees show neither in short-term nor in long-term a significant impact on workers’ participation.
Read article
Evaluation of Further Training Programmes with an Optimal Matching Algorithm
Eva Reinowski, Birgit Schultz, Jürgen Wiemers
IWH Discussion Papers,
No. 188,
2004
Abstract
This study evaluates the effects of further training on the individual unemployment duration of different groups of persons representing individual characteristics and some aspects of the economic environment. The Micro Census Saxony enables us to include additional information about a person's employment history to eliminate the bias resulting from unobservable characteristics and to avoid Ashenfelter's Dip. In order to solve the sample selection problem we employ an optimal full matching assignment, the Hungarian algorithm. The impact of participation in further training is evaluated by comparing the unemployment duration between participants and non-participants using the Kaplan-Meier-estimator. Overall, we find empirical evidence that participation in further training programmes results in even longer unemployment duration.
Read article