Success and risk factors in the pre-startup phase

Why does one person actually succeed in starting a business, while a second person gives up? In order to answer this question, a sample of 517 nascent entrepreneurs (people in the process of setting up a business) was followed over a three year period. After this period, it was established that 195 efforts were successful and that 115 startup efforts were abandoned. Our research focuses on estimating the relative importance of a variety of approaches and variables in explaining pre-startup success. These influences are organized in terms of Gartner's (1985) framework of new venture creation. This framework suggests that start-up efforts differ in terms of the characteristics of the individual(s) who start the venture, the organization which they create, the environment surrounding the new venture, and the process by which the new venture is started. Logistic regression analyses are run for the sample as a whole as well as for subgroups within the sample, namely for those with high ambition vs. low ambition and for those with substantial vs. limited experience. The results point to the importance of perceived risk of the market as a predictor of getting started vs. abandoning the startup effort

Setting Up a Business in the Netherlands

Why does one person actually succeed in starting a business, while a second gives up, and a third is still trying? To answer this question, a longitudinal study was set up in which 330 nascent entrepreneurs (people setting up a business) were followed over a one-year period. After one year, 47% actually started a business, 27% was still organizing, and 26% gave up the effort. In comparison to the two other groups, starters are different in terms of gender, industry experience, start-up capital, use of third party loans, sector and current activity

The role of dissatisfaction and per capita income in explaining self-employment across 15 european countries

This paper deals with explaining the sizable differences in the rate of self-employment (business ownership) across 15 European countries in the period 1978-2000, within a framework of occupational choice, focusing on the influence of dissatisfaction and of per capita income. Using two different measures of dissatisfaction, in addition to the level of economic development and controlling for several other variables, we find that, in addition to a negative and significant impact of per capita income, dissatisfaction at the level of societies has a positive and significant influence on self-employment levels. Both dissatisfaction with life and dissatisfaction with the way democracy works are found to influence self-employment. It is concluded that these are proxies for job dissatisfaction and at the same time represent other negative "displacements" known to promote self-employment. The findings indirectly point at the potential importance of push factors within the incentive structures of modern economies

Agility of vortex-based nanocontact spin torque oscillators

We study the agility of current-tunable oscillators based on a magnetic vortex orbiting around a point contact in spin-valves. Theory predicts frequency-tuning by currents occurs at constant orbital radius, so an exceptional agility is anticipated. To test this, we have inserted an oscillator in a microwave interferometer to apply abrupt current variations while time resolving its emission. Using frequency shift keying, we show that the oscillator can switch between two stabilized frequencies differing by 25% in less than ten periods. With a wide frequency tunability and a good agility, such oscillators possess desirable figures of merit for modulation-based rf applications.Comment: 3 pages, 3 figure

Color-Octet Fragmentation and the psi' Surplus at the Tevatron

The production rate of prompt $\psi'$'s at large transverse momentum at the Tevatron is larger than theoretical expectations by about a factor of 30. As a solution to this puzzle, we suggest that the dominant $\psi'$ production mechanism is the fragmentation of a gluon into a $c \bar c$ pair in a pointlike color-octet S-wave state, which subsequently evolves nonperturbatively into a $\psi'$ plus light hadrons. The contribution to the fragmentation function from this process is enhanced by a short-distance factor of $1/\alpha_s^2$ relative to the conventional color-singlet contribution. This may compensate for the suppression by $v^4$, where $v$ is the relative momentum of the charm quark in the $\psi'$. If this is indeed the dominant production mechanism at large $p_T$, then the prompt $\psi'$'s that are observed at the Tevatron should almost always be associated with a jet of light hadrons.Comment: 9 pages, LaTe

A Search for the Near-Infrared Counterpart to GCRT J1745-3009

We present an optical/near-infrared search for a counterpart to the perplexing radio transient GCRT J1745-3009, a source located ~1 degree from the Galactic Center. Motivated by some similarities to radio bursts from nearby ultracool dwarfs, and by a distance upper limit of 70 pc for the emission to not violate the 1e12 K brightness temperature limit for incoherent radiation, we searched for a nearby star at the position of GCRT J1745-3009. We found only a single marginal candidate, limiting the presence of any late-type star to >1 kpc (spectral types earlier than M9), >200 pc (spectral types L and T0-T4), and >100 pc (spectral types T4-T7), thus severely restricting the possible local counterparts to GCRT J1745-3009. We also exclude any white dwarf within 1 kpc or a supergiant star out to the distance of the Galactic Center as possible counterparts. This implies that GCRT J1745-3009 likely requires a coherent emission process, although whether or not it reflects a new class of sources is unclear.Comment: 10 pages, 5 figures. Accepted for publication in the Astrophysical Journa

Calculation of minor hysteresis loops under metastable to stable transformations in vortex matter

We present a model in which metastable supercooled phase and stable equilibrium phase of vortex matter coexist in different regions of a sample. Minor hysteresis loops are calculated with the simple assumption of the two phases of vortex matter having field-independent critical current densities. We use our earlier published ideas that the free energy barrier separating the metastable and stable phases reduces as the magnetic induction moves farther from the first order phase transition line, and that metastable to stable transformations occur in local regions of the sample when the local energy dissipation exceeds a critical value. Previously reported anomalous features in minor hysteresis loops are reproduced, and calculated field profiles are presented.Comment: 9pages, 7 figure

A Radial Velocity Study of Composite-Spectra Hot Subdwarf Stars with the Hobby-Eberly Telescope

Many hot subdwarf stars show composite spectral energy distributions indicative of cool main sequence companions. Binary population synthesis (BPS) models demonstrate such systems can be formed via Roche lobe overflow or common envelope evolution but disagree on whether the resulting orbital periods will be long (years) or short (days). Few studies have been carried out to assess the orbital parameters of these spectroscopic composite binaries; current observations suggest the periods are long. To help address this problem, we selected fifteen moderately-bright (V~13) hot subdwarfs with F-K dwarf companions and monitored their radial velocities (RVs) from January 2005 to July 2008 using the bench-mounted Medium Resolution Spectrograph on the Hobby-Eberly Telescope (HET). Here we describe the details of our observing, reduction, and analysis techniques and present preliminary results for all targets. By combining the HET data with recent observations from the Mercator telescope, we are able to calculate precise orbital solutions for three systems using more than 6 years of observations. We also present an up-to-date period histogram for all known hot subdwarf binaries, which suggests those with F-K main sequence companions tend to have orbital periods on the order of several years. Such long periods challenge the predictions of conventional BPS models, although a larger sample is needed for a thorough assessment of the models' predictive success. Lastly, one of our targets has an eccentric orbit, implying some composite-spectrum systems might have formerly been hierarchical triple systems, in which the inner binary merged to create the hot subdwarf.Comment: Published in The Astrophysical Journal, Volume 758, Issue 1, article id. 58 (2012). References updated and Equation (5) corrected. 12 pages, 5 figures, 5 table

Spatial structure of Mn-Mn acceptor pairs in GaAs

The local density of states of Mn-Mn pairs in GaAs is mapped with cross-sectional scanning tunneling microscopy and compared with theoretical calculations based on envelope-function and tight-binding models. These measurements and calculations show that the crosslike shape of the Mn-acceptor wavefunction in GaAs persists even at very short Mn-Mn spatial separations. The resilience of the Mn-acceptor wave-function to high doping levels suggests that ferromagnetism in GaMnAs is strongly influenced by impurity-band formation. The envelope-function and tight-binding models predict similarly anisotropic overlaps of the Mn wave-functions for Mn-Mn pairs. This anisotropy implies differing Curie temperatures for Mn $\delta$-doped layers grown on differently oriented substrates.Comment: 4 pages, 4 figure

The Value of Human and Social Capital Investments for the Business Performance of Start-ups

We investigate the manifold posed question: "To what extent does investment in human and social capital, besides the effect of "talent", enhance entrepreneurial performance?". We distinguish between three different performance measures: survival, profits, and generated employment. On the basis of the empirical analysis of a rich Dutch longitudinal data set of firm founders, we conclude that specific investments indeed affect the three performance measures sub- stantially and significantly. Specific attention is paid to the unobserved talent bias. Moreover, the effect of the emergence of so called "knowledge industries" is explored