43 research outputs found
Does the Support of Innovative Clusters Sustainably Foster R&D Activity? Evidence from the German BioRegio and BioProfile Contests
In this paper, we evaluate the R&D enhancing effects of two large public grant schemes aiming at encouraging the performance of firms organized in clusters. These are Germany's well known BioRegio and BioProfile contests for which we compare the research performance of winning regions in contrast with non-winning and non-participating comparison regions. We apply Difference-in-Difference estimation techniques in a generalized linear model framework, which allows to control for different initial regional conditions in the biotechnology related R&D activity. Our econometric findings support the view that winners generally outperform non-winning participants during the treatment period, thus indicating that exclusive funding as well as the stimulating effect of being a “winner" seems to work in the short-term. In contrast, no indirect impacts stemming from a potential mobilizing effect of the contest approaches have been detected. Also, we find only limited evidence for long-term effects of public R&D grants in the post-treatment period. The results of our analysis remain stable if we additionally augment the model to account for the particular role of spatial dependence in the R&D outcome variables.
Determinants of intraregional migration in Sub-Saharan Africa 1980-2000
Despite great accomplishments in the migration literature, the determinants of South-South migration remain poorly understood. In an attempt to fill this gap, this paper formulates and tests an empirical model for intraregional migration in sub-Saharan Africa within an extended human capital framework, taking into account spatial interaction. Using bilateral panel data between 1980 and 2000, we find that intraregional migration on the subcontinent is predominantly driven by economic opportunities and sociopolitics in the host country, facilitated by geographical proximity. The role played by network effects and environmental conditions is also apparent. Finally, origin and destination spatial dependence should definitely not be ignored
Endogeneity in Panel Data Models with Time-Varying and Time-Fixed Regressors: To IV or Not IV?
Long-term prognostic significance of HER-2/neu in untreated node-negative breast cancer depends on the method of testing
INTRODUCTION: The prognostic significance of HER-2/neu in breast cancer is a matter of controversy. We have performed a study in 101 node-negative breast cancer patients with long-term follow-up not treated in the adjuvant setting, and analysed the prognostic significance of immunohistochemistry (IHC) and fluorescence in situ hybridisation (FISH), both separately and in combination, in comparison with traditional prognostic factors. METHODS: Overexpression was classified semiquantitatively according to a score (0 to 3+) (HER-2_SCO). FISH was used to analyse HER2/neu amplification (HER-2_AMP). Patients classified 2+ by IHC were examined with FISH for amplification (HER-2_ALG). Patients with 3+ overexpression as well as amplification of HER-2/neu were positive for the combined variable HER2_COM. These variables were compared with tumour size, histological grade and hormone receptor status. RESULTS: HER-2_SCO was 3+ in 20% of all tumours. HER-2_ALG was positive in 22% and amplification (HER-2_AMP) was found in 17% of all tumours. Eleven percent of the tumours showed simultaneous 3+ overexpression and amplification. Only histological grade (relative risk [RR] 3.22, 95% confidence interval [CI] 1.73–5.99, P = 0.0002) and HER-2_AMP (RR 2.47, 95% CI 1.12–5.48, P = 0.026) were significant for disease-free survival in multivariate analysis. For overall survival, both histological grade (RR 3.89, 95% CI 1.77–8.55, P = 0.0007) and HER-2_AMP (RR 3.08, 95% CI 1.24–7.66, P = 0.016) retained their independent significance. CONCLUSION: The prognostic significance of HER-2/neu in node-negative breast cancer depends on the method of testing: only the amplification of HER-2/neu is an independent prognostic factor for the long-term prognosis of untreated node-negative breast cancer
The Effect of Tuition Fees on Student Enrollment and Location Choice – Interregional Migration, Border Effects and Gender Differences
Scientific collaboration between ‘old’ and ‘new’ member states: Did joining the European Union make a difference?
Scientific collaboration between ‘old’ and ‘new’ member states: Did joining the European Union make a difference?
This paper provides new insights on the effects of the enlargement of the European Union (EU) and European integration by investigating the issue of scientific collaboration within the new EU member states vis-à-vis the old EU member states. The question addressed is whether the EU membership following the two enlargement waves 2004 and 2007 has significantly increased the co-publication intensity of the new member states with other member countries. The empirical results based on data collected from the Web of Science database and Difference-in-Difference estimations point towards a conclusion that joining the EU indeed has had an additional positive impact on the co-publication intensity between the new and old member states and, in particular, within the new member states themselves. These results give tentative support for the successfulness of the EU’s science policies in achieving a common ‘internal market’ in research. We also find evidence for early anticipation effects of the consecutive EU accession