391 research outputs found
Did Processing Quota Damage Alaska Red King Crab Harvesters? Empirical Evidence
The Bering Sea and Aleutian Islands (BSAI) red king crab fisheries are managed with a controversial, market-based policy design, in which both individual transferable fishing and processing quotas are used. Despite the fact that the policy design maintains contestable markets, concern remains that the use of individual transferable processing quota (IPQ) damages harvesters who receive individual transferable fishing quota (IFQ). An integer, nonlinear optimization model that incorporates an empirically estimated, non-linear catch per unit effort function is developed to measure imputed IFQ values. The imputed quota values are based solely on harvesting efficiency in the absence of IPQs or potential wealth redistribution between sectors. Results are compared to a prerationalization optimization model and also to empirical quota trading prices in the presence of IPQs. This with and without analysis lends insight into whether and/or the extent to which IPQs damaged BSAI crab harvesters.Crab rationalization, IPQ, IFQ, imputed quota prices, harvesting efficiency., Environmental Economics and Policy, Public Economics, Q22, Q28, D61, C61, L78.,
Extension of the Poincar\'e group with half-integer spin generators: hypergravity and beyond
An extension of the Poincar\'e group with half-integer spin generators is
explicitly constructed. We start discussing the case of three spacetime
dimensions, and as an application, it is shown that hypergravity can be
formulated so as to incorporate this structure as its local gauge symmetry.
Since the algebra admits a nontrivial Casimir operator, the theory can be
described in terms of gauge fields associated to the extension of the
Poincar\'e group with a Chern-Simons action. The algebra is also shown to admit
an infinite-dimensional non-linear extension, that in the case of fermionic
spin- generators, corresponds to a subset of a contraction of two copies
of WB. Finally, we show how the Poincar\'e group can be extended with
half-integer spin generators for dimensions.Comment: 12 pages, no figures. Matches published versio
Toward the Integration of Economics and Outdoor Recreation Management
The general theme of this bulletin is that improved management of
public-sector recreational resources is a multidisciplinary task. To this
end, we attempt to integrate elements of outdoor recreation management
theory and economics. The bulletin is written for both resource managers
and researchers. For the former, our intent is to emphasize the importance
of being aware of economic implications-at least conceptually-of
management actions that influence the character and availability of recreational
opportunities. To researchers involved in developing recreation
management theory, we draw attention to the parallel between recreation
management theory and the traditional managerial economic model
of the firm. To economists, particularly those involved in developing
and applying nonmarket valuation techniques, we draw attention to the
types of decisions faced by resource managers.
We argue that the most important resource allocation issues are of
the incremental variety, so nonmarket valuation should also yield incremental
values. These values alone, however, are not sufficient
economic input into rational public choice analysis. The missing link ,
or nexus, between outdoor recreation management theory and economic
analysis is the integration of supply and demand, as called for by traditional
managerial economics. Collaborative research to develop recreation
supply response functions akin to agricultural production functions
is an essential step that is missing from both literatures. Theoretical and
applied work assume greater practical importance if they feed information
into this broadened framework. It is our hope that this bulletin will
bring the disciplines closer to that realization
Limits of three-dimensional gravity and metric kinematical Lie algebras in any dimension
We extend a recent classification of three-dimensional spatially isotropic
homogeneous spacetimes to Chern--Simons theories as three-dimensional gravity
theories on these spacetimes. By this we find gravitational theories for all
carrollian, galilean, and aristotelian counterparts of the lorentzian theories.
In order to define a nondegenerate bilinear form for each of the theories, we
introduce (not necessarily central) extensions of the original kinematical
algebras. Using the structure of so-called double extensions, this can be done
systematically. For homogeneous spaces that arise as a limit of (anti-)de
Sitter spacetime, we show that it is possible to take the limit on the level of
the action, after an appropriate extension. We extend our systematic
construction of nondegenerate bilinear forms also to all higher-dimensional
kinematical algebras.Comment: 52 pages, 2 figures, 11 tables; v2: matches published version,
additional references added and incorporated referee suggestion
Asymptotic structure of supergravity in 3D: extended super-BMS and nonlinear energy bounds
The asymptotically flat structure of supergravity in
three spacetime dimensions is explored. The asymptotic symmetries are spanned
by an extension of the super-BMS algebra, with two independent
currents of electric and magnetic type. These currents are associated to
fields being even and odd under parity, respectively. Remarkably, although the
fields do not generate a backreaction on the metric, they provide
nontrivial Sugawara-like contributions to the BMS generators, and hence to
the energy and the angular momentum. The entropy of flat cosmological
spacetimes with fields then acquires a nontrivial dependence on the
charges. If the spin structure is odd, the ground state
corresponds to Minkowski spacetime, and although the anticommutator of the
canonical supercharges is linear in the energy and in the electric-like
charge, the energy becomes bounded from below by the energy of the
ground state shifted by the square of the electric-like charge. If
the spin structure is even, the same bound for the energy generically holds,
unless the absolute value of the electric-like charge is less than minus the
mass of Minkowski spacetime in vacuum, so that the energy has to be
nonnegative. The explicit form of the Killing spinors is found for a wide class
of configurations that fulfills our boundary conditions, and they exist
precisely when the corresponding bounds are saturated. It is also shown that
the spectra with periodic or antiperiodic boundary conditions for the fermionic
fields are related by spectral flow, in a similar way as it occurs for the
super-Virasoro algebra. Indeed, our super-BMS algebra can
be recovered from the flat limit of the superconformal algebra with
, truncating the fermionic generators of the right copy.Comment: 32 pages, no figures. Talk given at the ESI Programme and Workshop
"Quantum Physics and Gravity" hosted by ESI, Vienna, June 2017. V3: minor
changes and typos corrected. Matches published versio
Revisiting the asymptotic dynamics of General Relativity on AdS
The dual dynamics of Einstein gravity on AdS supplemented with boundary
conditions of KdV-type is identified. It corresponds to a two-dimensional field
theory at the boundary, described by a novel action principle whose field
equations are given by two copies of the "potential modified KdV equation". The
asymptotic symmetries then transmute into the global Noether symmetries of the
dual action, giving rise to an infinite set of commuting conserved charges,
implying the integrability of the system. Noteworthy, the theory at the
boundary is non-relativistic and possesses anisotropic scaling of Lifshitz
type.Comment: 18 page
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