Zero-Group-Velocity acoustic waveguides for high-frequency resonators

The propagation of the Lamb-like modes along a silicon-on-insulator (SOI)/AlN thin supported structure was theoretically studied in order to exploit the intrinsic zero group velocity (ZGV) features to design electroacoustic resonators that do not require metal strip gratings or suspended edges to confine the acoustic energy. The ZGV resonant conditions in the SOI/AlN composite plate, i.e. the frequencies where the mode group velocity vanishes while the phase velocity remains finite, were investigated in the frequency range from few hundreds of MHz up to 1900 MHz. Some ZGV points were found that show up mostly in low-order modes. The thermal behaviour of these points was studied in the -30 to 220 {\deg}C temperature range and the temperature coefficients of the ZGV resonant frequencies (TCF) were estimated. The behaviour of the ZGV resonators operating as gas sensors was studied under the hypothesis that the surface of the device is covered with a thin polyisobutylene (PIB) film able to selectively adsorb dichloromethane (CH2Cl2), trichloromethane (CHCl3), carbontetrachloride (CCl4), tetrachloroethylene (C2Cl4), and trichloroethylene (C2HCl3). at atmospheric pressure and room temperature. The sensor sensitivity to gas concentration in air was theoretically estimated for the first four ZGV points of the inhomogeneous plate. The feasibility of high-frequency, low TCF electroacoustic micro-resonator based on SOI and piezoelectric thin film technology was demonstrated theoretically

Start-Up Subsidies in East Germany: Finally, a Policy that Works?

The German government has spent between 7bn and 11bn Euro per year on active labor market policies (ALMP) in East Germany in the last decade. The effectiveness of the most important programs (in terms of participants and spending) such as job-creation schemes and vocational training has been evaluated quite thoroughly in recent years. The results are disappointing, indicating that nearly all of these ‘traditional’ programs have to be rated as a failure. In light of these findings, policies to encourage unemployed people to become self-employed gained increasing importance. We present first evidence on the effectiveness of two start-up programs in East Germany. Our findings – even though partly preliminary – are rather promising, showing that these programs increase employment chances and earnings of participants. Hence, start-up subsidies might work even in a labor market with structural problems such as the one in East Germany.East Germany, effectiveness, evaluation, start-up subsidies, self-employment

Income support systems, labor market policies and labor supply: the German experience

In view of the demographic trends, most EU countries face the problem of a declining work force in the future. Understanding the interaction between income support systems (such as unemployment benefits, social assistance, early retirement and pension systems) and total labor supply is of crucial importance to combat problems and ensure economic growth in the future. The German labor market has been plagued by high and persistent unem­ployment in the last two decades in combination with a relatively low labor force participation of women. This created a situation where labor market reforms were unavoidable. The speed and depth of the reforms are remark­able, mainly aimed at activating people by increasing their incentives to take up work. The aim of this paper is to give a brief overview of the German income support systems and labor market polices, their recent reforms and—where already possible—effects of these reforms. Overall, Germany seems to be on the right track. The recent reforms helped to tackle some labor market problems but also created high political unrest. It remains to be seen how future governments react to worsened economic conditions in light of these experiences.Unemployment; Labor force participation; labor supply; benefit systems; public policy

Optimal control with switches in the objective functional

This note offers a proof of the necessary conditions for optimal control problems that involve a finite number of discrete switches in the objective functional over the planning horizon.necessary conditions

Income Support Systems, Labor Market Policies and Labor Supply: The German Experience

In view of the demographic trends, most EU countries face the problem of a declining work force in the future. Understanding the interaction between income support systems (such as unemployment benefits, social assistance, early retirement and pension systems) and total labor supply is of crucial importance to combat problems and ensure economic growth in the future. The German labor market has been plagued by high and persistent unemployment in the last two decades in combination with a relatively low labor force participation of women. This created a situation where labor market reforms were unavoidable. The speed and depth of the reforms are remarkable, mainly aimed at activating people by increasing their incentives to take up work. The aim of this paper is to give a brief overview of the German income support systems and labor market polices, their recent reforms and – where already possible – effects of these reforms. Overall, Germany seems to be on the right track. The recent reforms helped to tackle some labor market problems but also created high political unrest. It remains to be seen how future governments react to worsened economic conditions in light of these experiences.unemployment, labor force participation, labor supply, benefit systems, public policy

Self-Employment Dynamics, State Dependence and Cross-Mobility Patterns

This paper analyzes the mobility between self-employment, wage employment and non-employment. Using data for men in West Germany, we find strong true state dependence in all three states. Moreover, compared to wage employment, non-employment increases the probability of self-employment significantly, and selfemployment goes along with a higher risk of future non-employment.Self-Employment, State Dependence, Labor Market Dynamics, Unemployment

Evaluating the German "Mini-Job" Reform Using a True Natural Experiment

Increasing work incentives for people with low incomes is a common topic in the policy debate across European countries. The "Mini-Job" reform in Germany - introduced on April 1, 2003 - can be seen in line with these policies, exempting labour income below a certain threshold from taxes and employees' social security contributions. We carry out an ex-post evaluation to identify the short-run effects of this reform. Our identification strategy uses an exogenous variation in the interview months in the German Socio-Economic Panel, that allows us to distinguish groups that are (or are not) affected by the reform. To account for seasonal effects we additionally use a difference-in-differences strategy. The results show that the short-run effects of the reform are limited. We find no significant short-run effects for marginal employment. However, there is evidence that single men who are already employed react immediately and increase secondary job holding.Evaluation, natural experiment, difference-in-differences, marginal employment

The microeconometric estimation of treatment effects : an overview

Vocational training programmes have been the most important active labour market policy instrument in Germany in the last years. However, the still unsatisfying situation of the labour market has raised doubt on the efficiency of these programmes. In this paper, we analyse the effects of the participation in vocational training programmes on the duration of unemployment in Eastern Germany. Based on administrative data for the time between the October 1999 and December 2002 of the Federal Employment Administration, we apply a bivariate mixed proportional hazards model. By doing so, we are able to use the information of the timing of treatment as well as observable and unobservable influences to identify the treatment effects. The results show that a participation in vocational training prolongates the unemployment duration in Eastern Germany. Furthermore, the results suggest that locking-in effects are a serious problem of vocational training programmes. JEL Classification: J64, J24, I28, J6

Fat Chance! Obesity and the Transition from Unemployment to Employment

This paper focuses on estimating the magnitude of any potential weight discrimination by examining whether obese job applicants in Germany get treated or behave differently from non-obese applicants. Based on two waves of rich survey data from the IZA Evaluation dataset, which includes measures that control for education, demographic characteristics, labor market history, psychological factors and health, we estimate differences in job search behavior and labor market outcomes between obese/overweight and healthy weight individuals. Unlike other observational studies which are generally based on obese and non-obese individuals who might already be at different points in the job ladder (e.g., household surveys), in our data, individuals are newly unemployed and all start from the same point. The only subgroup we find in our data experiencing any possible form of labor market discrimination is obese women. Despite making more job applications and engaging more in job training programs, we find some indications that they experienced worse (or at best similar) employment outcomes than healthy weight women. Obese women who found a job also had significantly lower wages than healthy weight women.obesity, discrimination, employment, labor demand