Necessity and Opportunity Entrepreneurs and their Duration in Self-employment: Evidence from German Micro Data

Using data from the German Socio-Economic Panel Study (GSOEP), we analyze whether necessity entrepreneurs differ from opportunity entrepreneurs in terms of self-employment duration. Using univariate statistics, we find that opportunity entrepreneurs remain in self-employment longer than necessity entrepreneurs. However, after controlling for the entrepreneurs’ education in the professional area where they start their venture, this effect is no longer significant. We therefore conclude that the difference observed is not an original effect but rather is due to selection. We then go on to discuss the implications of our findings for entrepreneurship-policy making, and give suggestions to improve governmental start-up programs

Determinanten des Erfolgs staatlich geförderter Existenzgründungen – eine empirische Untersuchung

Ein Großteil der Neugründungen in Deutschland ist auf staatliche Förderung von Existenzgründern zurückzuführen. Dieser Anteil hat sich nach Einführung des als „Ich-AG“ bekannten Existenzgründungszuschusses Anfang 2003 stark erhöht. Die Erfolgsfaktorenforschung hat diese Form von Gründungen bislang jedoch wenig untersucht. Im Rahmen einer großzahligen Befragung von geförderten Existenzgründern untersucht dieser Beitrag die Erfolgsdeterminanten solcher geförderter Existenzgründungen. Die Ergebnisse der Analyse zeigen, dass der Gewinn aus der Existenzgründung bei älteren Gründern und bei Gründern mit einer langen Phase der Arbeitslosigkeit vor der Gründung seltener beziehungsweise erst später zur Bestreitung des Lebensunterhalts ausreicht. Dies gilt auch für Franchisegründungen und für Gründungen durch Frauen. In Bezug auf Bildungsvariablen, Gründungserfahrung und Teamgründungen im Vergleich zu Einzelgründungen wurde kein Effekt gefunden. Vorhandene Branchenerfahrung wirkt sich hingegen positiv auf den Erfolg der Gründung aus, Gründungs- und Führungserfahrung dagegen nicht. Die Implikationen unserer Ergebnisse für die Entrepreneurship-Forschung sowie für die Entrepreneurship-Praxis werden diskutiert. Herausforderungen aus Sicht der Gründungspolitik werden aufgezeigt.A large number of new ventures in Germany are undertaken due to government aid. With the introduction of the “Ich-AG” or “me-plc” in January 2003, this share has increased strongly. Entrepreneurship research so far has said very little about the success and the determinants of success of these types of start-ups. With this study, we aim to close this gap. We analyze the success and the determinants of success of these new ventures in a large scale survey of founders that have received governmental aid for their start-up. Our results show that the income generated by the venture is less likely to cover the costs of living in particular for elderly founders and for those founders that have experienced a long period of unemployment before they started their venture. This finding is also true for new ventures founded by women as well as for franchise start-ups. As concerns formal education, founder experience, and the fact whether the venture is founded by a team or not no significant effects exist. Industry experience, however, has a significant positive effect on the success of the new venture whereas founding and management experience have no effect. We discuss the implications of our findings from a perspective of entrepreneurship research as well as from a perspective of governmental start-up policy

Determinanten des Erfolgs staatlich geförderter Existenzgründungen – eine empirische Untersuchung

Ein Großteil der Neugründungen in Deutschland ist auf staatliche Förderung von Existenzgründern zurückzuführen. Dieser Anteil hat sich nach Einführung des als „Ich-AG“ bekannten Existenzgründungszuschusses Anfang 2003 stark erhöht. Die Erfolgsfaktorenforschung hat diese Form von Gründungen bislang jedoch wenig untersucht. Im Rahmen einer großzahligen Befragung von geförderten Existenzgründern untersucht dieser Beitrag die Erfolgsdeterminanten solcher geförderter Existenzgründungen. Die Ergebnisse der Analyse zeigen, dass der Gewinn aus der Existenzgründung bei älteren Gründern und bei Gründern mit einer langen Phase der Arbeitslosigkeit vor der Gründung seltener beziehungsweise erst später zur Bestreitung des Lebensunterhalts ausreicht. Dies gilt auch für Franchisegründungen und für Gründungen durch Frauen. In Bezug auf Bildungsvariablen, Gründungserfahrung und Teamgründungen im Vergleich zu Einzelgründungen wurde kein Effekt gefunden. Vorhandene Branchenerfahrung wirkt sich hingegen positiv auf den Erfolg der Gründung aus, Gründungs- und Führungserfahrung dagegen nicht. Die Implikationen unserer Ergebnisse für die Entrepreneurship-Forschung sowie für die Entrepreneurship-Praxis werden diskutiert. Herausforderungen aus Sicht der Gründungspolitik werden aufgezeigt.A large number of new ventures in Germany are undertaken due to government aid. With the introduction of the “Ich-AG” or “me-plc” in January 2003, this share has increased strongly. Entrepreneurship research so far has said very little about the success and the determinants of success of these types of start-ups. With this study, we aim to close this gap. We analyze the success and the determinants of success of these new ventures in a large scale survey of founders that have received governmental aid for their start-up. Our results show that the income generated by the venture is less likely to cover the costs of living in particular for elderly founders and for those founders that have experienced a long period of unemployment before they started their venture. This finding is also true for new ventures founded by women as well as for franchise start-ups. As concerns formal education, founder experience, and the fact whether the venture is founded by a team or not no significant effects exist. Industry experience, however, has a significant positive effect on the success of the new venture whereas founding and management experience have no effect. We discuss the implications of our findings from a perspective of entrepreneurship research as well as from a perspective of governmental start-up policy.Entrepreneurship; Self-employment; Necessity Entreptreneurship; Entrepreneurship Policy; Determinants of Success

Dynamics of Nanometer-Scale Foil Targets Irradiated with Relativistically Intense Laser Pulses

In this letter we report on an experimental study of high harmonic radiation generated in nanometer-scale foil targets irradiated under normal incidence. The experiments constitute the first unambiguous observation of odd-numbered relativistic harmonics generated by the $\vec{v}\times\vec{B}$ component of the Lorentz force verifying a long predicted property of solid target harmonics. Simultaneously the observed harmonic spectra allow in-situ extraction of the target density in an experimental scenario which is of utmost interest for applications such as ion acceleration by the radiation pressure of an ultraintense laser.Comment: 5 pages, 4 figure

Energy-Based switches losses model for the optimization of PwrSoC buck converter

Current trends in automotive industry impose as main drivers the improvement of the efficiency and the miniaturization of the electronic systems. New technologies for passives enable the integration of inductor based power converter together with the load in a single chip. Due to the complexity of the system and various constraints, multi-variable optimization needs to be employed. This study presents an energy-based piece-wise linear model for switches losses estimation for 40 nm automotive approved semiconductor technology used for implementation of PwrSoC buck converter system. The model, based on discrete number of calculations performed with Spice simulations, is presented in detail in this study and it is validated experimentally

Laser Induced Non-Sequential Double Ionization Investigated at and Below the Threshold for Electron Impact Ionization

We use correlated electron–ion momentum measurements to investigate laserinduced non-sequential double ionization of Ar and Ne. Light intensities are chosen in a regime at and below the threshold where, within the rescattering model, electron impact ionization of the singly charged ion core is expected to become energetically forbidden. Yet we find Ar2+ ion momentum distributions and an electron–electron momentum correlation indicative of direct impactionization. Within the quasistatic model this may be understood by assuming that the electric field of the light wave reduces the ionization potential of the singly charged ion core at the instant of scattering. The width of the projection of the ion momentum distribution onto an axis perpendicular to the light beam polarization vector is found to scalewiththe square root of the peak electric field strength in the light pulse. A scaling like this is not expected from the phase space available after electron impact ionization. It may indicate that the electric field at the instant of scattering is usually different fromzero and determines the transverse momentum distribution. A comparison of our experimental results with several theoretical results is give

Retrospective, observational study in patients receiving a dexamethasone intravitreal implant 0.7 mg for macular oedema secondary to retinal vein occlusion

PURPOSE To retrospectively evaluate the re-injection interval, efficacy and safety of dexamethasone (DEX) intravitreal implant 0.7 mg in the treatment of macular oedema (ME) due to retinal vein occlusion (RVO) in Germany in 2009-2012. METHODS Retrospective, multicentre, anonymised observational study of data collected from the first DEX implant 0.7 mg injection through 3-6 months following the last injection. Data were included if the patient was \textgreater18 years old, had a diagnosis of ME secondary to branch or central RVO, and received at least 2 DEX implant 0.7 mg injections during routine practice. RESULTS Data from 87 patients were analysed. Mean time to re-injection between first and second treatments was 5.03 months in the total RVO population, and 5.46 and 4.52 months for the branch and central RVO subpopulations, respectively. An intraocular pressure increase of \textgreater25 mm Hg was recorded in 20% of patients, and 34% of patients began treatment with anti-glaucoma medication, but surgery was not needed for this condition. CONCLUSIONS DEX implant 0.7 mg was found to be well tolerated and effective with repeat treatments in clinical practice

Stable laser-ion acceleration in the light sail regime

We present experimental results on ion acceleration with circularly polarized, ultrahigh contrast laser pulses focused to peak intensities of 5×1019 W cm-2 onto polymer targets of a few 10 nanometer thickness. We observed spatially and energetically separated protons and carbon ions that accumulate to pronounced peaks around 2 MeV containing as much as 6.5% of the laser energy. Based on particle-in-cell simulation, we illustrate that an early separation of heavier carbon ions and lighter protons creates a stable interface that is maintained beyond the end of the radiation pressure dominated acceleration process