408 research outputs found
Trends in Competitive Balance: Is There Evidence for Growing Imbalance in Professional Sport Leagues?
The concept of competitive balance is a central aspect in the literature of sports economics. A popular argumentation of sport functionaries is that dominance of one or a few teams could lead to unequal incomes for the clubs, restrictions in the clubs' ability to improve sporting performance and ultimately to a loss of attractiveness and loss of income for the league. Following this line of reasoning and alleging a negative trend in competitive sports functionaries often try to implement regulations in team sport leagues. The aim of this paper is to analyze for eight different leagues if there is such a trend existing. For an empirical test for trends in competitive balance of four European soccer leagues (ENG, ESP, GER, ITA) and four US Major Leagues (MLB, NBA, NFL, NHL), OLS regressions with a constant were carried out. For the entire observation period from 1969/70 to 2003/2004, of 48 trends ascertained, only 12 could be observed as being significantly positive (i.e. growing imbalance) with 19 significantly negative (i.e. growing balance). The remaining 17 trends were insignificantly different from zero
Episodic vertical nutrient fluxes and nearshore phytoplankton blooms in Southern California
Author Posting. © Association for the Sciences of Limnology and Oceanography, 2012. This article is posted here by permission of Association for the Sciences of Limnology and Oceanography for personal use, not for redistribution. The definitive version was published in Limnology and Oceanography 57 (2012): 1673-1688, doi:10.4319/lo.2012.57.6.1673.Three distinct phytoplankton blooms lasting 4–9 d were observed in approximately 15-m water depth near Huntington Beach, California, between June and October of 2006. Each bloom was preceded by a vertical NO3 flux event 6–10 d earlier. NO3 concentrations were estimated using a temperature proxy that was verified by comparison with the limited NO3 observations. The lower–water-column vertical NO3 flux from vertical advection was inferred from observed vertical isotherm displacement. Turbulent vertical eddy diffusivity was parameterized based on the observed background (< 0.3 cycles h−1) stratification and vertical shear in the horizontal currents. The first vertical nitrate flux event in June contained both advective and turbulent fluxes, whereas the later two events were primarily turbulent, driven by shear in the lower part of the water column. The correlation between the NO3 flux and the observed chlorophyll a (Chl a) was maximum (r2 = 0.40) with an 8-d lag. A simple nitrate–phytoplankton model using a linear uptake function and driven with the NO3 flux captured the timing, magnitude, and duration of the three Chl a blooms (skill = 0.61) using optimal net growth rate parameters that were within the expected range. Vertical and horizontal advection of Chl a past the measurement site were too small to explain the observed Chl a increases during the blooms. The vertical NO3 flux was a primary control on the growth events, and estimation of both the advective (upwelled) and turbulent fluxes is necessary to best predict these episodic blooms.California Sea Grant,
National Oceanic and Atmospheric Administration, California
Coastal Conservancy, National Science Foundation, and the
Office of Naval Research supported this research
Better Baltic Sea wave forecasts: improving resolution or introducing ensembles?
The performance of short-range operational forecasts of
significant wave height (SWH) in the Baltic Sea is evaluated. Forecasts produced
by a base configuration are intercompared with forecasts from two improved
configurations: one with improved horizontal and spectral resolution and one
with ensembles representing uncertainties in the physics of the forcing wind
field and the initial conditions of this field. Both of the improved forecast
classes represent an almost equal increase in computational costs. Therefore, the
intercomparison addresses the question of whether more computer
resources would be more favorably spent on enhancing the spatial and spectral
resolution or, alternatively, on introducing ensembles. The intercomparison
is based on comparisons with hourly observations of significant wave height
from seven observation sites in the Baltic Sea during the 3-year period from
2015 to 2017. We conclude that for most wave measurement sites, the
introduction of ensembles enhances the overall performance of the forecasts,
whereas increasing the horizontal and spectral resolution does not. These
sites represent offshore conditions, in that they are well exposed from all directions, are a
large distance from the nearest coast and in deep water. Therefore,
there is the a priori expectation that a detailed shoreline and bathymetry will not have
any impact. Only at one site do we find that increasing the horizontal and
spectral resolution significantly improves the forecasts. This site is
situated in nearshore conditions, close to land and a nearby island, and is
therefore shielded from many directions. Consequently, this study concludes that
to improve wave forecasts in offshore areas, ensembles should be introduced.
For near shore areas, in comparison, the study suggests that additional computational
resources should be used to increase the resolution.</p
Viable tax constitutions
Taxation is only sustainable if the general public complies with it. This observation is uncontroversial with tax practitioners but has been ignored by the public finance tradition, which has interpreted tax constitutions as binding contracts by which the power to tax is irretrievably conferred by individuals to government, which can then levy any tax it chooses. However, in the absence of an outside party enforcing contracts between members of a group, no arrangement within groups can be considered to be a binding contract, and therefore the power of tax must be sanctioned by individuals on an ongoing basis. In this paper we offer, for the first time, a theoretical analysis of this fundamental compliance problem associated with taxation, obtaining predictions that in some cases point to a re-interptretation of the theoretical constructions of the public finance tradition while in others call them into question
On Ignorant Voters and Busy Politicians
We show that a large electorate of ignorant voters can succeed in establishing high levels of electoral accountability. In our model an incumbent politician is confronted with a large number of voters who receive very noisy signals about her performance. We find that the accountability problem can be solved well in the sense that the incumbent exerts effort as if she faced a social planner who receives a perfect signal about her performance. Our results thus shed light on another potential blessing of large electorates in addition to information aggregation as postulated by the jury theorem
Episodic vertical nutrient fluxes and nearshore phytoplankton blooms
Abstract Three distinct phytoplankton blooms lasting 4-9 d were observed in approximately 15-m water depth near Huntington Beach, California, between June and October of 2006. Each bloom was preceded by a vertical NO 3 flux event 6-10 d earlier. NO 3 concentrations were estimated using a temperature proxy that was verified by comparison with the limited NO 3 observations. The lower-water-column vertical NO 3 flux from vertical advection was inferred from observed vertical isotherm displacement. Turbulent vertical eddy diffusivity was parameterized based on the observed background (, 0.3 cycles h 21 ) stratification and vertical shear in the horizontal currents. The first vertical nitrate flux event in June contained both advective and turbulent fluxes, whereas the later two events were primarily turbulent, driven by shear in the lower part of the water column. The correlation between the NO 3 flux and the observed chlorophyll a (Chl a) was maximum (r 2 5 0.40) with an 8-d lag. A simple nitrate-phytoplankton model using a linear uptake function and driven with the NO 3 flux captured the timing, magnitude, and duration of the three Chl a blooms (skill 5 0.61) using optimal net growth rate parameters that were within the expected range. Vertical and horizontal advection of Chl a past the measurement site were too small to explain the observed Chl a increases during the blooms. The vertical NO 3 flux was a primary control on the growth events, and estimation of both the advective (upwelled) and turbulent fluxes is necessary to best predict these episodic blooms
Energy funneling in a bent chain of Morse oscillators with long-range coupling
A bent chain of coupled Morse oscillators with long-range dispersive
interaction is considered. Moving localized excitations may be trapped in the
bending region. Thus chain geometry acts like an impurity. An energy funneling
effect is observed in the case of random initial conditions.Comment: 6 pages, 12 figures. Submitted to Physical Review E, Oct. 13, 200
Hamiltonian Hopf bifurcations in the discrete nonlinear Schr\"odinger trimer: oscillatory instabilities, quasiperiodic solutions and a 'new' type of self-trapping transition
Oscillatory instabilities in Hamiltonian anharmonic lattices are known to
appear through Hamiltonian Hopf bifurcations of certain time-periodic solutions
of multibreather type. Here, we analyze the basic mechanisms for this scenario
by considering the simplest possible model system of this kind where they
appear: the three-site discrete nonlinear Schr\"odinger model with periodic
boundary conditions. The stationary solution having equal amplitude and
opposite phases on two sites and zero amplitude on the third is known to be
unstable for an interval of intermediate amplitudes. We numerically analyze the
nature of the two bifurcations leading to this instability and find them to be
of two different types. Close to the lower-amplitude threshold stable
two-frequency quasiperiodic solutions exist surrounding the unstable stationary
solution, and the dynamics remains trapped around the latter so that in
particular the amplitude of the originally unexcited site remains small. By
contrast, close to the higher-amplitude threshold all two-frequency
quasiperiodic solutions are detached from the unstable stationary solution, and
the resulting dynamics is of 'population-inversion' type involving also the
originally unexcited site.Comment: 25 pages, 11 figures, to be published in J. Phys. A: Math. Gen.
Revised and shortened version with few clarifying remarks adde
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