The effect of unemployment benefit II sanctions on reservation wages

"In 2005, benefit sanctions in Germany were tightened with the introduction of the new means-tested unemployment benefit II (UB II), codified in Social Code (SC) II. This study analyzes the effect of benefit sanctions on the reservation wage of sanctioned unemployment benefit II recipients. The behavioral effect of a benefit sanction is an empirically open question. According to job search theory, benefit sanctions directly reduce reservation wages. To explore this hypothesis, propensity score matching is adopted. The dataset used is a unique survey of UB II recipients in the first year of SC II. For the identification of the effect, the study relies on the rich individual data and the rather unsystematic sanctioning process in the starting months after the introduction of the SC II. The timing of the sanction is explicitly considered by estimating the effects for the first four quarters of UB II receipt in 2005. The main result is that there was no significant effect of sanctions on the reservation wages of sanctioned unemployment benefit II recipients. A side result is that sanctioned UB II recipients were not more likely to be employed at the time of their interview either. Both results are robust to various matching estimators, estimation specifications and to the timing of the UB II sanction." (Author's abstract, IAB-Doku) ((en))Arbeitslosengeld II-Empfänger, Leistungsbezug, Sanktion - Auswirkungen, Einkommenserwartung, Verhaltensänderung, Erwerbsverhalten, Arbeitsplatzsuchtheorie

Interplay of Aharonov-Bohm and Berry phases in gate-defined graphene quantum dots

We study the influence of a magnetic flux tube on the possibility to electrostatically confine electrons in a graphene quantum dot. Without magnetic flux tube, the graphene pseudospin is responsible for a quantization of the total angular momentum to half-integer values. On the other hand, with a flux tube containing half a flux quantum, the Aharonov-Bohm phase and Berry phase precisely cancel, and we find a state at zero angular momentum that cannot be confined electrostatically. In this case, true bound states only exist in regular geometries for which states without zero-angular-momentum component exist, while non-integrable geometries lack confinement. We support these arguments with a calculation of the two-terminal conductance of a gate-defined graphene quantum dot, which shows resonances for a disc-shaped geometry and for a stadium-shaped geometry without flux tube, but no resonances for a stadium-shaped quantum dot with a $\pi$-flux tube.Comment: 7 pages, 5 figure

A simple Hidden Markov Model for midbrain dopaminergic neurons

Poster presentation: Introduction Dopaminergic neurons in the midbrain show a variety of firing patterns, ranging from very regular firing pacemaker cells to bursty and irregular neurons. The effects of different experimental conditions (like pharmacological treatment or genetical manipulations) on these neuronal discharge patterns may be subtle. Applying a stochastic model is a quantitative approach to reveal these changes. ..

A model for the joint evaluation of burstiness and regularity in oscillatory spike trains

Poster presentation: Introduction The ability of neurons to emit different firing patterns is considered relevant for neuronal information processing. In dopaminergic neurons, prominent patterns include highly regular pacemakers with separate spikes and stereotyped intervals, processes with repetitive bursts and partial regularity, and irregular spike trains with nonstationary properties. In order to model and quantify these processes and the variability of their patterns with respect to pharmacological and cellular properties, we aim to describe the two dimensions of burstiness and regularity in a single model framework. Methods We present a stochastic spike train model in which the degree of burstiness and the regularity of the oscillation are described independently and with two simple parameters. In this model, a background oscillation with independent and normally distributed intervals gives rise to Poissonian spike packets with a Gaussian firing intensity. The variability of inter-burst intervals and the average number of spikes in each burst indicate regularity and burstiness, respectively. These parameters can be estimated by fitting the model to the autocorrelograms. This allows to assign every spike train a position in the two-dimensional space described by regularity and burstiness and thus, to investigate the dependence of the firing patterns on different experimental conditions. Finally, burst detection in single spike trains is possible within the model because the parameter estimates determine the appropriate bandwidth that should be used for burst identification. Results and Discussion We applied the model to a sample data set obtained from dopaminergic substantia nigra and ventral tegmental area neurons recorded extracellularly in vivo and studied differences between the firing activity of dopaminergic neurons in wildtype and K-ATP channel knock-out mice. The model is able to represent a variety of discharge patterns and to describe changes induced pharmacologically. It provides a simple and objective classification scheme for the observed spike trains into pacemaker, irregular and bursty processes. In addition to the simple classification, changes in the parameters can be studied quantitatively, also including the properties related to bursting behavior. Interestingly, the proposed algorithm for burst detection may be applicable also to spike trains with nonstationary firing rates if the remaining parameters are unaffected. Thus, the proposed model and its burst detection algorithm can be useful for the description and investigation of neuronal firing patterns and their variability with cellular and experimental conditions

The effect of unemployment benefit II sanctions on reservation wages

"In 2005, benefit sanctions in Germany were tightened with the introduction of the new means-tested unemployment benefit II (UB II), codified in Social Code (SC) II. This study analyzes the effect of benefit sanctions on the reservation wage of sanctioned unemployment benefit II recipients. The behavioral effect of a benefit sanction is an empirically open question. According to job search theory, benefit sanctions directly reduce reservation wages. To explore this hypothesis, propensity score matching is adopted. The dataset used is a unique survey of UB II recipients in the first year of SC II. For the identification of the effect, the study relies on the rich individual data and the rather unsystematic sanctioning process in the starting months after the introduction of the SC II. The timing of the sanction is explicitly considered by estimating the effects for the first four quarters of UB II receipt in 2005. The main result is that there was no significant effect of sanctions on the reservation wages of sanctioned unemployment benefit II recipients. A side result is that sanctioned UB II recipients were not more likely to be employed at the time of their interview either. Both results are robust to various matching estimators, estimation specifications and to the timing of the UB II sanction." (author's abstract)Im Jahr 2000 wurden mit der Einführung von Arbeitslosengeld II (ALG II) die Sanktionsmöglichkeiten gegenüber ALG II-Empfängern verschärft. Der Beitrag untersucht die Auswirkung einer solchen ALG II-Sanktion auf den Reservationslohn sanktionierter ALG II-Empfänger. Empirisch sind die Verhaltensauswirkungen infolge von Sanktionen bislang nicht zufriedenstellend geklärt; Auswirkungen auf den Reservationslohn sind noch vollkommen unerforscht. Suchtheoretisch führen Sanktionen direkt zu einem Sinken der Reservationslöhne. Zur Überprüfung dieser Hypothese wird der Effekt von ALG II-Sanktionen auf den Reservationslohn mittels Propensity Score Matching geschätzt. Die verwendete Datengrundlage ist ein Querschnittsdatensatz von ALG II-Empfängern im ersten Jahr nach der Einführung von ALG II. Die Fülle der im Datensatz verfügbaren Variablen und der in der Einführungsphase von ALG II noch unsystematische Sanktionsprozess ermöglichen die Identifizierung des Sanktionseffektes. Hierbei wird das Timing der Sanktion explitzit berücksichtigt. Als wichtigstes Ergebnis zeigt sich, dass sich keine signifikanten Auswirkungen der Sanktionen auf den Reservationslohn sanktionierter arbeitsloser Arbeitslosengeld II-Empfänger nachweisen lassen. Ein weiteres interessantes Ergebnis ist, dass die Wahrscheinlichkeit einer Beschäftigung zum Zeitpunkt des Interviews für sanktionierte Arbeitslosengeld II-Empfänger nicht höher war. Beide Ergebnisse sind robust gegenüber verschiedenen Spezifikationen des Matching-Schätzers und gegenüber dem Timing der Sanktionen. (IAB