15,559 research outputs found
The Impact of the Internet on Retail Competition: Evidence from Technological Differences in Internet Access
Does the internet increase competition? To address this question, I exploit two institutional details unique to Germany: (1) Some municipalities received glass fibre cables that cannot be upgraded to DSL; I use these municipalities as a treatment group with reduced online competition. (2) German law mandates resale price maintenance for books; I compare three retailing sectors, electronics (price competition), books (no price competition), and food (no online sales), to identify the effect of price competition: The effect of price competition is highly significant. Full broadband access reduces offline electronics retailers’ producer rents by 1.5 percent per year from 1999 to 2007
Differential Pricing Policy
Differential pricing is a valid means of improving profits, keeping the total cost of air transportation down, and making it possible for more people to use air transportation
The Supermassive Black Hole and Dark Matter Halo of NGC 4649 (M60)
We apply the axisymmetric orbit superposition modeling to estimate the mass
of the supermassive black hole and dark matter halo profile of NGC 4649. We
have included data sets from the Hubble Space Telescope, stellar, and globular
cluster observations. Our modeling gives the black hole mass = 4.5 \pm 1.0 10^9
\Msun and M/L = 8.7 \pm 1.0 (or 8.0 \pm 0.9 after foreground Galactic
extinction is corrected). We confirm the presence of a dark matter halo, but
the stellar mass dominates inside the effective radius. The parameters of the
dark halo are less constrained due to the sparse globular cluster data at large
radii. We find that in NGC 4649 the dynamical mass profile from our modeling is
consistently larger than that derived from the X-ray data over most of the
radial range by roughly 60% to 80%. It implies that either some forms of
non-thermal pressure need to be included, the assumed hydrostatic equilibrium
may not be a good approximation in the X-ray modelings of NGC 4649, or our
assumptions used in the dynamical models are biased. Our new black hole mass is
about two times larger than the previous published value; the earlier model did
not adequately sample the orbits required to match the large tangential
anisotropy in the galaxy center. If we assume that there is no dark matter, the
results on the black hole mass and M/L do not change significantly, which we
attribute to the inclusion of HST spectra, the sparse globular cluster
kinematics, and a diffuse dark matter halo. Without the HST data, the
significance of the black hole detection is greatly reduced.Comment: Accepted for publication in ApJ. emulateapj format. 11 page
A Soft Budget Constraint Explanation for the Venture Capital Cycle
We explore why venture capital funds limit the amount of capital they raise and do not reinvest the proceeds. This structure is puzzling because it leads to a succession of several funds financing each new venture which multiplies the well known agency problems. We argue that an inside investor cannot provide a hard budget constraint while a less well informed outsider can. Therefore, the venture capitalist delegates the continuation decision to the outsider by ex ante restricting the amount of capital he has under management. The soft budget constraint problem becomes the more important the higher the entrepreneur’s private benefits are and the higher the probability of failure of a project is.Contract Theory; Corporate Finance; Venture Capital
The Impact of the Internet on Retail Competition: Evidence from Technological Differences in Internet Access
Does the internet increase competition? To address this question, I exploit two institutional details unique to Germany: (1) Some municipalities received glass fibre cables that cannot be upgraded to DSL; I use these municipalities as a treatment group with reduced online competition. (2) German law mandates resale price maintenance for books; I compare three retailing sectors, electronics (price competition), books (no price competition), and food (no online sales), to identify the effect of price competition: The effect of price competition is highly significant. Full broadband access reduces offline electronics retailers’ producer rents by 1.5 percent per year from 1999 to 2007.Internet; Market Structure; Retail Competition; Differences in Differences
Zappa-Sz\'ep products of Garside monoids
A monoid is the internal Zappa-Sz\'ep product of two submonoids, if every
element of admits a unique factorisation as the product of one element of
each of the submonoids in a given order. This definition yields actions of the
submonoids on each other, which we show to be structure preserving.
We prove that is a Garside monoid if and only if both of the submonoids
are Garside monoids. In this case, these factors are parabolic submonoids of
and the Garside structure of can be described in terms of the Garside
structures of the factors. We give explicit isomorphisms between the lattice
structures of and the product of the lattice structures on the factors that
respect the Garside normal forms. In particular, we obtain explicit natural
bijections between the normal form language of and the product of the
normal form languages of its factors.Comment: Published versio
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