5,835 research outputs found
Mixed Strategies in Discriminatory Divisible-good Auctions
Author: Edward J. Anderson, Pär Holmberg and Andrew B. Philpott Keywords: Pay-as-bid Auction; Divisible Good Auction; Mixed Strategy Equilibria; Wholesale Electricity Markets Pages: 71 Published: November 24, 2009 JEL-codes: D43; D44; C72 Download Wp814.pdf (756 kB) Abstract Using the concept of market-distribution functions, we derive general optimality conditions for discriminatory divisible-good auctions, which are also applicable to Bertrand games and non-linear pricing. We introduce the concept of offer distribution function to analyze randomized offer curves, and characterize mixed-strategy Nash equilibria for pay-as-bid auctions where demand is uncertain and costs are common knowledge; a setting for which pure-strategy supply function equilibria typically do not exist. We generalize previous results on mixtures over horizontal offers as in Bertrand-Edgeworth games, but more importantly we characterize novel mixtures over partly increasing supply functions.Pay-as-bid Auction; Divisible Good Auction; Mixed Strategy Equilibria; Wholesale Electricity Markets
Relaxing competition through speculation: Committing to a negative supply slope
We demonstrate how suppliers can take strategic speculative positions in derivatives markets to soften competition in the spot market. In our game, suppliers first choose a portfolio of call options and then compete with supply functions. In equilibrium firms sell forward contracts and buy call options to commit to downward sloping supply functions. Although this strategy is risky, it reduces the elasticity of the residual demand of competitors, who increase their mark-ups in response. We show that this type of strategic speculation increases the level and volatility of commodity prices and decreases welfare
Analyzing the Settlement Pattern of the Burnt Hill Study Area
This article examines the strategies used by communities of farmers when faced wih economic decline. This is accomplished by analyzing historic map data from 1850-1940 to recreate and interpret settlement changes
Jeans instability of a galactic disk embedded in a live dark halo
We investigate the Jeans instability of a galactic disk embedded in a
dynamically responsive dark halo. It is shown that the disk-halo system becomes
nominally Jeans unstable. On small scales the instability is suppressed, if the
Toomre stability index Q_T is higher than a certain threshold, but on large
scales the Jeans instability sets invariably in. However, using a simple
self-consistent disk-halo model it is demonstrated that this occurs on scales
which are much larger than the system so that this is indeed only a nominal
effect. From a practical point of view the Jeans instability of galactic disks
is not affected by a live dark halo.Comment: 3 pages, 1 figure, accepted by Astron. Astrophy
An Astronomical Pattern-Matching Algorithm for Automated Identification of Whale Sharks
The largest shark species alive today, whale sharks (Rhincodon typus) are rare and poorly studied. Directed fisheries, high value in international trade, a highly migratory nature, and generally low abundance make this species vulnerable to exploitation. Mark- and-recapture studies have provided our current understanding of whale shark demographics and life history, but conventional tagging has met with limited success. To aid in conservation and management efforts, and to further our knowledge of whale shark biology, an identification technology that maximizes the scientific value of individual sighting is needed
The Geneva-Copenhagen Survey of the Solar neighbourhood II. New uvby calibrations and rediscussion of stellar ages, the G dwarf problem, age-metallicity diagram, and heating mechanisms of the disk
Ages, metallicities, space velocities, and Galactic orbits of stars in the
Solar neighbourhood are fundamental observational constraints on models of
galactic disk evolution. We aim to consolidate the calibrations of uvby
photometry into Te, [Fe/H], distance, and age for F and G stars and rediscuss
the results of the Geneva-Copenhagen Survey (Nordstrom et al. 2004; GCS) in
terms of the evolution of the disk.
We substantially improve the Te and [Fe/H] calibrations for early F stars,
where spectroscopic temperatures have large systematic errors. Our recomputed
ages are in excellent agreement with the independent determinations by Takeda
et al. (2007), indicating that isochrone ages can now be reliably determined.
The revised G-dwarf metallicity distribution remains incompatible with
closed-box models, and the age-metallicity relation for the thin disk remains
almost flat, with large and real scatter at all ages (sigma intrinsic = 0.20
dex). Dynamical heating of the thin disk continues throughout its life;
specific in-plane dynamical effects dominate the evolution of the U and V
velocities, while the W velocities remain random at all ages. When assigning
thick and thin-disk membership for stars from kinematic criteria, parameters
for the oldest stars should be used to characterise the thin disk.Comment: Accepted for publication in A&A on June 20, 200
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