2,211 research outputs found
Revenue Sharing in Professional Sports Leagues: For the Sake of Competitive Balance or as a Result of Monopsony Power?
We analyze the distribution of broadcasting revenues by sports leagues.In the context of an isolated league, we show that when the teams engage in competitive bidding to attract talent, the league's optimal choice is full revenue sharing (resulting in full competitive balance) even if the revenues are independent of the level of balancedness.This result is overturned when the league has no monopsony power in the talent market.When the teams of two different leagues bid for talent, the equilibrium level of revenue sharing is bounded away from the full sharing of revenues: leagues choose a performance-based reward scheme.Finally, we argue that our model explains the observed differences in revenue sharing rules used by the U.S. sports leagues (full revenue sharing) and European soccer leagues (performance-based reward).broadcasting industry;sport;competition;revenue sharing
Collective vs Individual Sale of TV Rights in League Sports
In many countries, the collective sale of TV rights by sports leagues has been challenged by the antitrust authorities.In several cases, however, leagues won in court, on the ground that sport cannot be considered a standard good.In this paper, we investigate the conditions under which the sale of TV rights collectively by sports leagues, rather than individually by teams, is preferred from a social welfare viewpoint.We find that collective sale is socially preferable when leagues are small, relatively homogeneous in terms of clout and where teams get little performance-related revenues.broadcasting industry;sport;broadcasting rights
Pull-in control due to Casimir forces using external magnetic fields
We present a theoretical calculation of the pull-in control in capacitive
micro switches actuated by Casimir forces, using external magnetic fields. The
external magnetic fields induces an optical anisotropy due to the excitation of
magneto plasmons, that reduces the Casimir force. The calculations are
performed in the Voigt configuration, and the results show that as the magnetic
field increases the system becomes more stable. The detachment length for a
cantilever is also calculated for a cantilever, showing that it increases with
increasing magnetic field. At the pull-in separation, the stiffness of the
system decreases with increasing magnetic field.Comment: accepted for publication in App. Phys. Let
Arbitrage-free bond pricing with dynamic macroeconomic models
The authors examine the relationship between changes in short-term interest rates induced by monetary policy and the yields on long-maturity default-free bonds. The volatility of the long end of the term structure and its relationship with monetary policy are puzzling from the perspective of simple structural macroeconomic models. The authors explore whether richer models of risk premiums, specifically stochastic volatility models combined with Epstein-Zin recursive utility, can account for such patterns. They study the properties of the yield curve when inflation is an exogenous process and compare this with the yield curve when inflation is endogenous and determined through an interest rate (Taylor) rule. When inflation is exogenous, it is difficult to match the shape of the historical average yield curve. Capturing its upward slope is especially difficult because the nominal pricing kernel with exogenous inflation does not exhibit any negative autocorrelation-a necessary condition for an upward-sloping yield curve, as shown in Backus and Zin. Endogenizing inflation provides a substantially better fit of the historical yield curve because the Taylor rule provides additional flexibility in introducing negative autocorrelation into the nominal pricing kernel. Additionally, endogenous inflation provides for a flatter term structure of yield volatilities, which better fits historical bond data.Bonds - Prices ; Macroeconomics
High-Q Gold and Silicon Nitride Bilayer Nanostrings
Low-mass, high-Q, silicon nitride nanostrings are at the cutting edge of
nanomechanical devices for sensing applications. Here we show that the addition
of a chemically functionalizable gold overlayer does not adversely affect the Q
of the fundamental out-of-plane mode. Instead the device retains its mechanical
responsiveness while gaining sensitivity to molecular bonding. Furthermore,
differences in thermal expansion within the bilayer give rise to internal
stresses that can be electrically controlled. In particular, an alternating
current excites resonant motion of the nanostring. This AC thermoelastic
actuation is simple, robust, and provides an integrated approach to sensor
actuation.Comment: 5 pages, 4 figures + supplementary materia
Collective vs Individual Sale of TV Rights in League Sports
In many countries, the collective sale of TV rights by sports leagues has been challenged by the antitrust authorities.In several cases, however, leagues won in court, on the ground that sport cannot be considered a standard good.In this paper, we investigate the conditions under which the sale of TV rights collectively by sports leagues, rather than individually by teams, is preferred from a social welfare viewpoint.We find that collective sale is socially preferable when leagues are small, relatively homogeneous in terms of clout and where teams get little performance-related revenues.
Sesgos en la obtención de estimas de densidad obtenidas por medio de transectos lineales en ambientes estepáricos de las Islas Canarias
We studied bias in density estimations derived from strip transects in dry open–country in the Canary Islands. We also present some critical remarks on GarcĂa–del–Rey’s (2005) paper regarding strip transects and the validity of comparisons based on population densities of birds in scrublands on Tenerife island using two different methods: territory mapping and strip transect sampling. Although strip transects with census belts of 25 m do not account for detectability, this method only slightly undervalues true density estimates, and allowed to detect more than 85% of birds present in poorly vegetated environments in the Canary Islands. Previously published works on distribution and abundance of terrestrial birds in the Canary Islands using the strip transect sampling with belts of 25 m on both sides of the observer, thus provide reliable information that only slightly underestimates true densities.
Key words: Birds, Canary Islands, Census methods, Strip transects, Open–country environments, Population
density, Territory mapping.We studied bias in density estimations derived from strip transects in dry open–country in the Canary Islands. We also present some critical remarks on GarcĂa–del–Rey’s (2005) paper regarding strip transects and the validity of comparisons based on population densities of birds in scrublands on Tenerife island using two different methods: territory mapping and strip transect sampling. Although strip transects with census belts of 25 m do not account for detectability, this method only slightly undervalues true density estimates, and allowed to detect more than 85% of birds present in poorly vegetated environments in the Canary Islands. Previously published works on distribution and abundance of terrestrial birds in the Canary Islands using the strip transect sampling with belts of 25 m on both sides of the observer, thus provide reliable information that only slightly underestimates true densities.
Key words: Birds, Canary Islands, Census methods, Strip transects, Open–country environments, Population
density, Territory mapping.Se estudian los sesgos derivados del empleo del mĂ©todo del taxiado (transectos lineales con bandas de 25 m a cada lado del observador) para obtener densidades en ambientes estepáricos de las Islas Canarias. TambiĂ©n se presentan algunos comentarios crĂticos al trabajo de GarcĂa–del–Rey (2005) que compara estimas de densidad obtenidas en Tenerife utilizando dos mĂ©todos diferentes: mapeo de territorios y transecto lineal. Aunque el mĂ©todo del taxiado estima densidades relativas no corregidas por la detectabilidad de las especies, este mĂ©todo proporciona valores de densidad muy parecidos a los reales, ya que permite detectar en ambientes con poca cobertura vegetal a más del 85% de los individuos dentro de bandas de 25 m a cada lado del observador. Por tanto, los trabajos previamente publicados sobre densidades de aves en Canarias proporcionan estimas fiables sĂłlo ligeramente infravaloradas.
Palabras clave: Aves, Islas Canarias, Métodos de censo, Transecto lineal, Ambientes estepáricos, Densidad
de poblaciĂłn, Mapeo de territorios
Thin-layer agar for detection of resistance to rifampicin, ofloxacin and kanamycin in Mycobacterium tuberculosis isolates
BACKGROUND: In low-income countries there is a great need for economical methods for testing the susceptibility of Mycobacterium tuberculosis to antibiotics. OBJECTIVE: To evaluate the thin-layer agar (TLA) for rapid detection of resistance to rifampicin (RMP), ofloxacin (OFX) and kanamycin (KM) in M. tuberculosis clinical isolates and to determine the sensitivity, specificity and time to positivity compared to the gold standard method. METHODS: One hundred and forty-seven clinical isolates of M. tuberculosis were studied. For the TLA method, a quadrant Petri plate containing 7H11 agar with RMP, OFX and KM was used. Results were compared to the Bactec MGIT960 for RMP and the proportion method for OFX and KM. RESULTS: The sensitivity and specificity for RMP and OFX were 100% and for KM they were 100% and 98.7%, respectively. The use of a TLA quadrant plate enables the rapid detection of resistance to the three anti-tuberculosis drugs RMP, OFX and KM in a median of 10 days. CONCLUSION: TLA was an accurate method for the detection of resistance in the three drugs studied. This faster method is simple to perform, providing an alternative method when more sophisticated techniques are not available in low-resource settings
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