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Abstract. This paper estimates the effects of knowledge spillovers on patent growth rates across 335 European regions over the 1989–1999 period. We propose a dynamic model based on an innovation production function. A Bayesian approach is used to take into account area‐specific innovation and spatial spillovers. The estimation of the model proceeds via Markov Chain Monte Carlo simulation. The results show significant positive and negative spatial effects on innovative activity. The model allows for a rich spatial specification, which we illustrate by incorporating transport proximity measured by transportation time between regions to augment the typical spatial proximity measure of connectivity between regions. Doing this produces more pronounced spatial spillovers that exhibit a more polarized spatial pattern than a model relying on spatial proximity alone.  相似文献   
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Domestication is an ongoing co-evolutionary process rather than an event or invention. Recent zooarchaeological and animal genetics research has prompted a thorough revision of our perspectives on the history of domestic animals in Africa. Genetic analyses of domestic animal species have revealed that domestic donkeys are descended from African ancestors, opened a debate over the contribution of indigenous aurochs to African domestic cattle, revealed an earlier and possibly exogenous origin of the domestic cat, and reframed our vision of African dogs. Genetic diversity studies and mapping of unique traits in African cattle, sheep, goats, pigs and chickens indicate adaptations to regional environmental challenges and suggest hitherto unknown and complex patterns of interactions both among Africans and with Southwest Asia and other Asian regions on the Indian Ocean. This article argues against the static perspective on domestication as invention and for viewing it as a dynamic, locally based and continuing process.  相似文献   
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DO FLOODS HAVE PERMANENT EFFECTS? EVIDENCE FROM THE NETHERLANDS   总被引:1,自引:0,他引:1  
This study investigates the short‐ and long‐run impact on population dynamics of the major flood in the Netherlands in 1953. A dynamic difference‐in‐differences analysis reveals that the flood had an immediate negative impact on population growth, but limited long‐term effects. In contrast, the resulting flood protection program (Deltaworks), had a persisting positive effect on population growth. As a result, there has been an increase in population in flood‐prone areas. Our results suggest a moral hazard effect of flood mitigation leading to more people locating in flood‐prone areas, increasing potential disaster costs.  相似文献   
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