27,069 research outputs found
Keys to Economics of Global Warming: A Critique of the Dismal Theorem
In a recent paper on climate change, M. Weitzman argues that the traditional cost-benefit analysis cannot be used as a reference tool for designing a climate change policy due to a large uncertainty that cannot be reduced by further analyses. The findings of the âDismal Theorem' are, however, based on two critical assumptions: a single geographical unit and two distinct points in time. It assumes a single geographical unit, disallowing the possibility of reallocating resources across different geographical regions under climate change. It also assumes only two time periods, the present and the year 2100, which rules out a dynamic dimension of climate policy such as burden sharing across generations and learning over time. On the empirical side, the author's apprehension of catastrophe is blown out of context since he assumes that all climate scenarios are equally likely to occur and that there would be no policy intervention to control greenhouse gases over time. Finally, impact studies do not support catastrophic results from climate change within this century.Climate Catastrophe, Dismal Theorem, Global Public Goods, Cost-Benefit Analysis.
A structural ricardian analysis of climate change impacts and adaptations in African agriculture
This paper develops a Structural Ricardian model to measure climate change impacts that explicitly models the choice of farm type in African agriculture. This two stage model first estimates the type of farm chosen and then the conditional incomes of each farm type after removing selection biases. The results indicate that increases in temperature encourage farmers to adopt mixed farming and avoid specialized farms such as crop-only or livestock-only farms. Increases in precipitation encourage farmers to shift from irrigated to rainfed crops. As temperatures increase, farm incomes from crop-only farms or livestock-only farms fall whereas incomes from mixed farms increase. With precipitation increases, farm incomes from irrigated farms fall whereas incomes from rainfed farms increase. Naturally, the Structural Ricardian model predicts much smaller impacts than a model that holds farm type fixed. With a hot dry climate scenario, the Structural Ricardian model predicts that farm income will fall 50 percent but the fixed farm type model predicts farm incomes will fall 75 percent.Crops&Crop Management Systems,Agriculture&Farming Systems,Livestock&Animal Husbandry,Climate Change,Rural Development Knowledge&Information Systems
Climate change impacts on Latin American farmland values: the role of farm type
This paper examines climate change impacts on South American agriculture using a set of Ricardian regressions estimated across different samples of farms in South America. Regressions are run for the whole sample and for subsamples of crop-only, mixed, and livestock-only farms. The results indicate that climate sensitivity varies a great deal across each type of farm. The analysis also reveals that the impacts will vary substantially across South America. The hot and wet Amazon and Equatorial regions are likely to lose the most from warming scenarios whereas the more temperate high elevation and southern regions of South America will likely gain.Climate change, Agriculture, South America, Environmental Economics and Policy,
Formulating the Net Gain of MISO-SFN in the Presence of Self-Interferences
In this study, an analytical formula for multiple-input single-output single frequency network gain (MISO-SFNG) is investigated. To formulate the net MISO-SFNG, we derived the average signal to interference plus noise ratio (SINR) where the gain achieved by the distributed MISO diversity as a function of power imbalance is curve-fitted. Further, we analyzed the losses owing to self-interferences resulting from the delay spread and imperfect channel estimation. We verified the accuracy and effectiveness of the derived formula by comparing the measurement results with the analytical results. The derived formula helps to understand how various system factors affect the gain under a given condition. The formula can be used to evaluate the MISO-SFNG and to predict the MISO-SFN coverage in various system configurations
Strong coupling theory of the spinless charges on the triangular lattices: possibility of a new quantum liquid
We propose a new type of charge liquid state in the spinless fermion system
on a triangular lattice under strong inter-site Coulomb interactions, . In
the strong coupling limit (), the ground state is classical and disordered
due to geometrical frustration. The introduction of small t will drive the
system to a partially ordered phase which we call a "pinball liquid". A
possibly long range ordered Wigner crystal solid coexist with a liquid
component which are moving around them like a pinball. This liquid is dominant
over wide range of filling, even away from the regular triangle, and is also
realized in the hard core boson systems. Relevance to the organic theta-ET_2X
is discsussed.Comment: 4pages, 7figure
Current-induced synchronized switching of magnetization
We investigate current-induced magnetization switching for a multilayer
structure that allows a reduced switching current while maintaining high
thermal stability of the magnetization. The structure consists of a
perpendicular polarizer, a perpendicular free-layer, and an additional
free-layer having in-plane magnetization. When the current runs perpendicular
to the structure, the in-plane free-layer undergoes a precession and supplies
an internal rf field to the perpendicular free-layer, resulting in a reduced
switching current for one current polarity. For the other polarity, the
in-plane free-layer almost saturates perpendicular to the plane and acts as
another perpendicular polarizer, which also reduces the switching current.Comment: 18 pages, 4 figure
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