Clustering life trajectories: A new divisive hierarchical clustering algorithm for discrete-valued discrete time series

A new algorithm for clustering life course trajectories is presented and tested with large register data. Life courses are represented as sequences on a monthly timescale for the working-life with an age span from 16-65. A meaningful clustering result for this kind of data provides interesting subgroups with similar life course trajectories. The high sampling rate allows precise discrimination of the different subgroups, but it produces a lot of highly correlated data for phases with low variability. The main challenge is to select the variables (points in time) that carry most of the relevant information. The new algorithm deals with this problem by simultaneously clustering and identifying critical junctures for each of the relevant subgroups. The developed divisive algorithm is able to handle large amounts of data with multiple dimensions within reasonable time. This is demonstrated on data from the Federal German pension insurance. --Clustering,measures of association,discrete data,time series

Fixing the leak: Unemployment incidence before and after the 2006 reform of unemployment benefits in Germany

"From 2002 - 2004, the German government passed several laws that curtailed the generosity of the unemployment compensation system. One of the most ambitious changes was a considerable reduction in unemployment benefit entitlement lengths for older unemployed, which was effective during 2006 and 2007. We apply a difference-in-differences approach to show that the highly disputed reform induced a considerable decline in unemployment incidence among older workers. It thus sealed an important leak in the unemployment insurance system. Furthermore, we find a strong anticipation effect; unemployment entries of elderly workers peaked during the months preceding the reform." (Author's abstract, IAB-Doku) ((en))ältere Arbeitnehmer, arbeitsmarktpolitische Maßnahme, Arbeitslosengeld, Leistungsbezug - Dauer, Wirkungsforschung

Fixing the leak: unemployment incidence before and after the 2006 reform of unemployment benefits in Germany

From 2002-2004, the German government passed several laws that curtailed the generosity of the unemployment compensation system. One of the most ambitious changes was a considerable reduction in unemployment benefit entitlement lengths for older unemployed, which was effective during 2006 and 2007. We apply a difference-in-differences approach to show that the highly disputed reform induced a considerable decline in unemployment incidence among older workers. It thus sealed an important leak in the unemployment insurance system. Furthermore, we find a strong anticipation effect; unemployment entries of elderly workers peaked during the months preceding the reform. --unemployment incidence,policy evaluation,administrative data

Clustering life trajectories : a new divisive hierarchical clustering algorithm for discrete-valued discrete time series

A new algorithm for clustering life course trajectories is presented and tested with large register data. Life courses are represented as sequences on a monthly timescale for the working-life with an age span from 16–65. A meaningful clustering result for this kind of data provides interesting subgroups with similar life course trajectories. The high sampling rate allows precise discrimination of the different subgroups, but it produces a lot of highly correlated data for phases with low variability. The main challenge is to select the variables (points in time) that carry most of the relevant information. The new algorithm deals with this problem by simultaneously clustering and identifying critical junctures for each of the relevant subgroups. The developed divisive algorithm is able to handle large amounts of data with multiple dimensions within reasonable time. This is demonstrated on data from the Federal German pension insurance

Give missings a chance: Combined stochastic and rule-based approach to improve regression models with mismeasured monotonic covariates without side information

Register data are known for their large sample size and good data quality. The measurement accuracy of variables highly depends on their high importance for administrative processes. The education variable in the IAB employment sub-sample is an example for information that is gathered without a clear purpose. It therefore severely suffers from missing values and misclassifications. In this paper, a classical approach to deal with incomplete data is used in combination with rule-based plausibility checks for misclassification to improve the quality of the variable. The developed correction procedure is applied to simple Mincer-type wage regressions. The procedure reveals that the quality of years in education is very important: The German labour market rewards general education less than vocational training. Furthermore, using this method, no indication of an inflation in formal education degrees could be found. --Measurement error,EM by the method of weights,wage regression,expansion of educational degrees,misclassification,imputation rules

Fixing the leak: unemployment incidence before and after the 2006 reform of unemployment benefits in Germany

"Das Gesetz zu Reformen am Arbeitsmarkt schränkte ab Februar 2006 die Bezugshöchstdauern des Arbeitslosengeldes für Ältere stark ein; je nach Altersgruppe um bis zu 14 Monate. Wir untersuchen dieses natürliche Experiment und zeigen: Bei den betroffenen Altersgruppen stiegen die Übergangsraten aus Beschäftigung in Arbeitslosigkeit in den drei Monaten vor der Reform deutlich an: Bei einem durchschnittlichen Arbeitnehmer der Altersgruppe 57 bis 64 war die monatliche Übergangswahrscheinlichkeit sogar um etwa 120 Prozent höher, als ohne Reform zu erwarten gewesen wäre. Im Nachreform-Zeitraum bis Ende 2007 sanken die monatlichen Eintrittsraten Älterer in Arbeitslosigkeit deutlich ab; sie lagen bei den 57-64 Jährigen um gut 20 Prozent niedriger als ohne Reform. Ein Teil der geringeren Eintritte im Nachreform-Zeitraum dürfte darauf zurückzuführen sein, dass Übergänge in die Monate vor der Reform vorgezogen wurden. Da der Gesetzgeber die Bezugshöchstdauern bereits Anfang 2008 teils wieder verlängerte, lässt sich der exakte langfristige Reformeffekt leider nicht identifizieren." (Autorenreferat)"From 2002-2004, the German government passed several laws that curtailed the generosity of the unemployment compensation system. One of the most ambitious changes was a considerable reduction in unemployment benefit entitlement lengths for older unemployed, which was effective during 2006 and 2007. We apply a difference-in-differences approach to show that the highly disputed reform induced a considerable decline in unemployment incidence among older workers. It thus sealed an important leak in the unemployment insurance system. Furthermore, we find a strong anticipation effect; unemployment entries of elderly workers peaked during the months preceding the reform." (author's abstract

Fixing the leak : unemployment incidence before and after the 2006 reform of unemployment benefits in Germany

From 2002–2004, the German government passed several laws that curtailed the generosity of the unemployment compensation system. One of the most ambitious changes was a considerable reduction in unemployment benefit entitlement lengths for older unemployed, which was effective during 2006 and 2007. We apply a difference-in-differences approach to show that the highly disputed reform induced a considerable decline in unemployment incidence among older workers. It thus sealed an important leak in the unemployment insurance system. Furthermore, we find a strong anticipation effect; unemployment entries of elderly workers peaked during the months preceding the reform

Give missings a chance : combined stochastic and rule-based approach to improve regression models with mismeasured monotonic covariates without side information

Register data are known for their large sample size and good data quality. The measurement accuracy of variables highly depends on their high importance for administrative processes. The education variable in the IAB employment sub-sample is an example for information that is gathered without a clear purpose. It therefore severely suffers from missing values and misclassifications. In this paper, a classical approach to deal with incomplete data is used in combination with rule-based plausibility checks for misclassification to improve the quality of the variable. The developed correction procedure is applied to simple Mincer-type wage regressions. The procedure reveals that the quality of years in education is very important: The German labour market rewards general education less than vocational training. Furthermore, using this method, no indication of an inflation in formal education degrees could be found

The sorting of female careers after first birth : a competing risks analysis of maternity leave duration

A number of contributions have found evidence for motherhood being a critical life event for women's employment careers. This study presents a detailed model for the du- ration of maternity leave in which young mothers can make a transition into a number of states related to employment and unemployment among others. The model incorporates a large number of factors including the legal framework, individual and firm character- istics. We provide a comprehensive picture of the sorting mechanisms that lead to the differentiation of women's employment careers after birth. Our empirical evidence is de- rived from large linked administrative individual labour market data from Germany for a period of three decades. We obtain unprecedented insights how women's skills, the quality of the previous job match, firm level characteristics, labour market conditions and leave legislation are related to the length of maternity duration

Generalised partially linear regression with misclassified data and an application to labour market transitions

We consider the semiparametric generalised linear regression model which has mainstream empirical models such as the (partially) linear mean regression, logistic and multinomial regression as special cases. As an extension to related literature we allow a misclassified covariate to be interacted with a nonparametric function of a continuous covariate. This model is tailormade to address known data quality issues of administrative labour market data. Using a sample of 20m observations from Germany we estimate the determinants of labour market transitions and illustrate the role of considerable misclassification in the educational status on estimated transition probabilities and marginal effects