13,035 research outputs found
MARKET PERFORMANCE WITH MULTIPRODUCT FIRMS
We revisit the fundamental issue of market provision of variety associated with Chamberlin, Spence, and Dixit and Stiglitz when firms sell several products. Both products and firms are envisaged as di?erentiated. We propose a nested demand model where consumers decide upon a firm then which variant to buy, and use it to determine the market’s biases when firms compete in product ranges and prices. The market system attracts too many firms with too few products per firm: firms restrain product ranges to relax price competition, but this exacerbates overentry. The results extend to generalized nested CES models.Multiproduct firms, excess variety, nested demand, product line competition
Information Congestion: open access in a two-sided market
Advertising messages compete for scarce attention. “Junk” mail, “spam” e-mail, and telemarketing calls need both parties to exert effort to generate transactions. Message recipients supply attention depending on average message benefit, while senders are motivated by profits. Costlier message transmission may improve message quality so more messages are examined. Too many messages may be sent, or the wrong ones. A Do-Not-Call policy beats a ban, but too many individuals opt out. A monopoly gatekeeper performs better than personal access pricing if nuisance costs to receivers are moderate.information overload, congestion, advertising, common property resource, two-sided markets, junk mail, email, telemarketing, Do Not Call List, message pricing policy.
Information Congestion
Advertising messages vie for scarce attention. “Junk” mail, “spam” e-mail, and telemarketing calls need both parties to exert effort to generate transactions. Message recipients supply attention depending on average message benefit, while senders are motivated by profits. Costlier message transmission may improve message quality so more messages are examined. Too many messages may be sent, or the wrong ones. A Do-Not-Call policy beats a ban, but too many individuals opt out. A monopoly gatekeeper performs better than personal access pricing if nuisance costs to receivers are moderate.
Information Congestion
Advertising messages compete for scarce attention. ?Junk? mail, ?spam? e-mail, and telemarketing calls need both parties to exert effort to generate transactions. Message recipients supply attention depending on average message beneÞt. Senders are motivated by proÞts. Costlier message transmission may improve message quality so more messages are examined. Too many messages may be sent, or the wrong ones. A Do-Not-Call policy beats a ban, but too many individuals opt out. A monopoly gatekeeper performs better than personal access pricing if nuisance costs are moderate. The medium is the message with multiple channels, and there is excessive indiscriminate mailing.information overload, congestion, advertising, common property resource, overÞshing, two-sided markets, junk mail, email, telemarketing, Do Not Call List, message pricing, the Medium is the Message, market research.
From Local to Global Competition
This paper lays out and elaborates upon the properties of an extended Chamberlinian model with applications both in Industrial Organization and Economic Geography/ Urban Economics. The framework is used to explain the impact of some major changes over the last two centuries: reductions in transport costs, increased taste for variety, population growth, and use of technologies with greater returns to scale. To this end, we introduce a framework that has known models of oligopolistic competition with differentiated products as limit cases. These limit models include the circle, the logit, and the CES models. The integrative approach incorporates both localized and global competition, as well as price-sensitive individual.Product Differentiation, Economic Geography, Spatial Competition, Localization, Monopolistic Competition
An efficient flamelet progress-variable method for modeling non-premixed flames in weak electric fields
Combustion stabilization and enhancement of the flammability limits are
mandatory objectives to improve nowadays combustion chambers. At this purpose,
the use of an electric field in the flame region provides a solution which is,
at the same time, easy to implement and effective to modify the flame
structure. The present work describes an efficient flamelet progress-variable
approach developed to model the fluid dynamics of flames immersed in an
electric field. The main feature of this model is that it can use complex
ionization mechanisms without increasing the computational cost of the
simulation. The model is based on the assumption that the combustion process is
not directly influenced by the electric field and has been tested using two
chemi-ionization mechanisms of different complexity in order to examine its
behavior with and without the presence of heavy anions in the mixture. Using a
one- and two-dimensional numerical test cases, the present approach has been
able to reproduce all the major aspects encountered when a flame is subject to
an imposed electric field and the main effects of the different chemical
mechanisms. Moreover, the proposed model is shown to produce a large reduction
in the computational cost, being able to shorten the time needed to perform a
simulation up to 40 times.Comment: 26 pages, 13 figures, paper accepted for publication on Computers and
Fluid
Influence of electromagnetic interferences on the gravimetric sensitivity of surface acoustic waveguides
Surface acoustic waveguides are increasing in interest for (bio)chemical
detection. The surface mass modification leads to measurable changes in the
propagation properties of the waveguide. Among a wide variety of waveguides,
Love mode has been investigated because of its high gravimetric sensitivity.
The acoustic signal launched and detected in the waveguide by electrical
transducers is accompanied by an electromagnetic wave; the interaction of the
two signals, easily enhanced by the open structure of the sensor, creates
interference patterns in the transfer function of the sensor. The influence of
these interferences on the gravimetric sensitivity is presented, whereby the
structure of the entire sensor is modelled. We show that electromagnetic
interferences generate an error in the experimental value of the sensitivity.
This error is different for the open and the closed loop configurations of the
sensor. The theoretical approach is completed by the experimentation of an
actual Love mode sensor operated under liquid in open loop configuration. The
experiment indicates that the interaction depends on the frequency and the mass
modifications.Comment: 28 pages, 8 figure
Information Congestion
Advertising messages vie for scarce attention. “Junk” mail, “spam” e-mail, and telemarketing calls need both parties to exert effort to generate transactions. Message recipients supply attention depending on average message benefit, while senders are motivated by profits. Costlier message transmission may improve message quality so more messages are examined. Too many messages may be sent, or the wrong ones. A Do-Not-Call policy beats a ban, but too many individuals opt out. A monopoly gatekeeper performs better than personal access pricing if nuisance costs to receivers are moderate
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