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

The Burdwood Bank Circulation

A suite of high-resolution numerical simulations characterizes the oceanic circulation in the Burdwood Bank, a shallow seamount located in the northeastern end of the Drake Passage. Model analysis shows energetic upwelling and mixing uplifting deep and benthic waters into the photic layer. Tides and the Antarctic Circumpolar Current are the primary drivers of the bank's circulation. Tidal forcing is the main driver for the entrainment of deep waters into the upper layers of the bank and local wind forcing for the detrainment of these waters into the deep ocean. Passive tracer diagnostics suggest that the dynamical processes triggered by the Burdwood Bank could have a significant impact on local ecosystems and the biogeochemical balance of the southwestern Atlantic region, which is one of the most fertile portions of the Southern Ocean. Model results are robust—they are reproduced in a wide array of model configurations—but there is insufficient observational evidence to corroborate them. Satellite color imagery does not show substantial chlorophyll blooms in this region but it shows strong phytoplankton plumes emanating from the bank. There are several potential explanations for the chlorophyll deficit, including lack of light due to persistent cloud cover, deep mixing layers, fast ocean currents, and the likelihood that blooms, while extant, might not develop on the surface. None of these possibilities can be confirmed at this stage.Fil: Matano, Ricardo P.. State University of Oregon; Estados UnidosFil: Palma, Elbio Daniel. Universidad Nacional del Sur. Departamento de Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; ArgentinaFil: Combes, Vincent. State University of Oregon; Estados Unido