Disasters and economic welfare : can national savings help explain post-disaster changes in consumption ?

The debate on whether natural disasters cause significant macroeconomic impacts and indeed hinder development is ongoing. Most analyses along these lines have focused on impacts on gross domestic product. This paper looks beyond this standard national accounting aggregate, and examines whether traditional and alternative national savings measures combined with adjustments for the destruction of capital stocks may contribute to better explaining post-disaster changes in welfare as measured by changes in consumption expenditure. The author concludes that including disaster asset losses may help to better explain variations in post-disaster consumption, albeit almost exclusively for the group of low-income countries. The observed effect is rather small and in the range of a few percent of the explained variation. For low-income countries, capital stock and changes therein, such as forced by disaster shocks, seem to play a more important role than for higher-income economies, where human capital and technological progress become crucial. There are important data constraints and uncertainties, particularly regarding the quality of disaster loss data and the shares of capital stock losses therein. Another important challenge potentially biasing the results is the lack of data on alternative savings measures for many disaster-exposed lower-income countries and small island states.Hazard Risk Management,Natural Disasters,Economic Theory&Research,,Emerging Markets

Optimization of periodic single-photon sources

We introduce a theoretical framework which is suitable for the description of all spatial and time-multiplexed periodic single-photon sources realized or proposed thus far. Our model takes into account all possibly relevant loss mechanisms. This statistical analysis of the known schemes shows that multiplexing systems can be optimized in order to produce maximal single-photon probability for various sets of loss parameters by the appropriate choice of the number of multiplexed units of spatial multiplexers or multiplexed time intervals and the input mean photon pair number, and reveals the physical reasons of the existence of the optimum. We propose a novel time-multiplexed scheme to be realized in bulk optics, which, according to the present analysis, would have promising performance when experimentally realized. It could provide a single-photon probability of 85\% with a choice of experimental parameters which are feasible according to the experiments known from the literature.Comment: 13 pages, 18 figure

Disasters and Economic Welfare: Can National Savings Explain Post-disaster Changes in Consumption?

The debate on whether natural disasters cause significant macroeconomic impacts and indeed hinder devlopment is ongoing. Most analyses along these lines have focused on impacts on gross domestic product. This paper looks beyond this standard national accounting aggregate, and examines whether traditional and alternative national savings measures combined with adjustments for the destruction of capital stocks may contribute to better explaining post-disaster changes in welfare as measured by changes in consumption expenditure. The author concludes that including disaster asset losses may help to better explain variations in post-disaster consumption, albeit almost exclusvely for the group of low-income countries. The observed effect is rather small and in the range of few percent of the explained variation. For low-income countries, capital stock and changes therein, such as forced by disaster shocks, seem to play a more important role than for higher-income economies where human capital and technological progress become crucial. There are important data constraints and uncertainties, particularly regarding the quality of disaster loss data and the shares of capital stock losses therein. Another important challenge potentially biasing the results is the lack of data on alternative savings measures for many disaster-exposed lower-income countries and small island states

Macroeconomic impacts of natural disasters

This paper discusses the macroeconomic effects that a number of developing countries, subject to substantial natural disaster risk, may experience after disasters. Further, the paper recommends the need to plan the recovery process on a macroeconomic basis. These points are substantiated with examples from recent experience in Honduras and El Salvador

Optimization of periodic single-photon sources based on combined multiplexing

We consider periodic single-photon sources with combined multiplexing in which the outputs of several time-multiplexed sources are spatially multiplexed. We give a full statistical description of such systems in order to optimize them with respect to maximal single-photon probability. We carry out the optimization for a particular scenario which can be realized in bulk optics and its expected performance is potentially the best at the present state of the art. We find that combined multiplexing outperforms purely spatially or time multiplexed sources for certain parameters only, and we characterize these cases. Combined multiplexing can have the advantages of possibly using less nonlinear sources, achieving higher repetition rates, and the potential applicability for continuous pumping. We estimate an achievable single-photon probability between 85% and 89%.Comment: 11 pages, 6 figur