Suchergebnisse

Abstract
Using a newly assembled data set of US patents, we show that innovation activity is less concentrated in high-density locations than commonly believed. Yet, inventions based on atypical combinations of knowledge are indeed more prevalent in high-density urban centres. To interpret this relation, we propose that informal interactions in densely populated areas help knowledge flows between distant fields, but are less relevant for flows between close fields. We build a model of innovation in a spatial economy that endogenously generates the pattern observed in the data: specialised clusters emerge in low-density areas, whereas high-density locations diversify and produce unconventional ideas.

The World Bank and the IMF have adopted a debt sustainability framework (DSF) to evaluate the risk of debt distress in Low Income Countries (LICs). At the core of the DSF are empirically-based thresholds for each of five different measures of the debt burden (the ?debt threshold approach? DTA). The DSF contains a rule for aggregating the information contained in these five different variables which we label the ?worst-case aggregator? (WCA) in view of the fact that the DSF considers a breach of any one of the thresholds sufficient to indicate a high risk of debt distress. However, neither the

For Afghanistan, the dual prospect of declining donor support and high ongoing security spending over the medium term keeps the government budget tight. This paper uses a general equilibrium model to capture the security-development tradeoff facing the government in its effort to rehabilitate macroeconomic stability and welfare. In particular, it considers strategic policy options for counteracting and minimizing the negative macroeconomic impact of possible aid and revenue shortfalls. We find that the mobilization of domestic revenues through changes in tax policy is the preferred policy resp