COMMENT: EFFICIENCY OF ITQS IN THE PRESENCE OF PRODUCTION EXTERNALITIES

Resource /Energy Economics and Policy,

Using Participation Data to Estimate Fishing Costs for Commercial Salmon Fisheries in Alaska

This paper estimates the fishing costs and the returns to fishing for nine commercial salmon fleets in Alaska. The econometric model uses a two-stage least squares estimation procedure to estimate the effect of congestion and heterogeneity on the returns to fishermen. The hypotheses that fishermen are homogenous and that there is no congestion externality present in the fisheries are strongly rejected. The data indicates that fishermen are quite heterogeneous in fishing skill levels. This difference accounts for the overall estimates of positive net returns to the common property fisheries. Estimates of the net returns to the fisheries suggest that the returns to different gear types vary largely. The set net fleets are found to have the highest return as a percentage of total revenues.Fishing costs, econometric model, heterogeneity, skill rents, commercial salmon fisheries, Environmental Economics and Policy, Production Economics,

Good Fences Make Good Neighbors: Endogenous Property Rights in a Game of Conflict

This paper derives the conditions under which property rights can arise in an anarchy equilibrium. The creation of property rights requires that players devote part of their endowment to the public good of property rights protection. In the Nash equilibrium, players contribute zero to the protection of property rights. In contrast, a king who provides property rights protection paid for by a tax on endowments can completely eliminate conflict, but such a king has an incentive to take the surplus for himself. Thus players have an incentive to find a solution that keeps power in their own hands. In a social contract, players first credibly commit part of their endowments to providing property rights and then allocate the balance of their endowments between production and conflict. While property rights can arise under a social contract if the productivity of resources relative to the size of the population is sufficiently high, these property rights may be less than perfectly secure. Nevertheless, for sufficiently high productivity of resources relative to the size of the population, the social contract welfare dominates autocracy. Key Words:

Electromagnetic response of high-Tc superconductors -- the slave-boson and doped-carrier theories

We evaluate the doping dependence of the quasiparticle current and low temperature superfluid density in two slave-particle theories of the tt't''J model -- the slave-boson theory and doped-carrier theory. In the slave-boson theory, the nodal quasiparticle current renormalization factor $\alpha$ vanishes proportionally to the zero temperature superfluid density $\rho_S(0)$; however, we find that away from the $\rho_S(0) \to 0$ limit $\alpha$ displays a much weaker doping dependence than $\rho_S(0)$. A similar conclusion applies to the doped-carrier theory, which differentiates the nodal and antinodal regions of momentum space. Due to its momentum space anisotropy, the doped-carrier theory enhances the value of $\alpha$ in the hole doped regime, bringing it to quantitative agreement with experiments, and reproduces the asymmetry between hole and electron doped cuprate superconductors. Finally, we use the doped-carrier theory to predict a specific experimental signature of local staggered spin correlations in doped Mott insulator superconductors which, we propose, should be observed in STM measurements of underdoped high-Tc compounds. This experimental signature distinguishes the doped-carrier theory from other candidate mean-field theories of high-Tc superconductors, like the slave-boson theory and the conventional BCS theory.Comment: 12 pages, RevTeX4, homepage http://dao.mit.edu/~we

The Education of the Deaf: Past, Present, Future*

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Goals of the Congress

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Challenge and Opportunity

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