MOND predictions of "halo" phenomenology in disc galaxies

We examine two corollaries of MOND pertaining to the properties of the equivalent dark-matter halo. MOND predicts for pure exponential discs a tight relation involving the halo and disc scale lengths and the mean acceleration in the disc, which we find to test favorably against the Verheijen sample of Ursa Major galaxies. A correlation between halo and disc length scales is also apparent when the "maximum disc" contribution is assumed, but we demonstrate that this follows from the more general MOND prediction. The second MOND prediction involves the existence of a maximum halo acceleration, which also tests favorably against the Ursa Major sample for different assumptions on the disc contribution.Comment: 5 pages, 4 eps figures, uses mn2e.cls (submitted to MNRAS

Organizing Production in a Large Economy with Costly Communication

We show that in a large production economy, the cost of collecting the information required by a planner to set nearly optimal prices is negligible relative to the total output of the economy. The cost of collecting the information required to set a nearly optimal production plan for each firm in the economy is not negligible. This conclusion stands in contrast to common opinion that determining optimal prices requires as much information as determining an optimal plan

Auction Design Enhancements for Non-Combinatorial Auctions

We evaluate a number of possible enhancements to the FCC auctions. We consider only changes to the current auction rules that stay within the basic format of the simultaneous multiple round auction for individual licenses. This report summarizes and extends our e-mail exchanges with FCC staff on this topic. A subsequent report will cover auctions with combination bids. Overall, the FCC spectrum auctions have been an enormous success. However, there are two design goals in the auction where important improvement can be achieved within the basic rules structure. These are restricting collusion among bidders and reducing the time taken to complete the auction. This report focuses on enhancements that help to achieve these two goals. Some of the suggested changes also streamline the auction process so large auctions can be conducted more quickly without sacrificing efficiency.Auctions; Spectrum Auctions; Multiple-Round Auctions; Efficiency

Package Bidding for Spectrum Licenses

The FCC was an innovator in adopting the rules of the simultaneous ascending-price auction for its sales of spectrum licenses. While these rules have performed well in the auctions conducted so far (and would perform even better with the design improvements suggested in our first report), there are two inherent limitations in any design that seeks to assign and price the licenses individually. First, such designs create strategic incentives for bidders interested in multiple licenses that are substitutes to reduce their demands for some of the licenses in order to reduce the final prices of the others; this is the demand reduction problem. Second, even if bidders behave non-strategically, there is a fundamental problem with the basic concept of individual-license pricing when licenses are complementary. In simultaneous ascending-price auctions, from a bidder's perspective this is the exposure problem. A bidder who is unsuccessful in bidding for a large package of licenses may be left with a partial package whose total price cannot be justified in the absence of those complementary licenses it failed to win. This problem is present in any auction mechanism that sells licenses individually, with no opportunity to bid on packages. In this report our task is confined to analyses of the merits of package bidding and the practical problems of implementation. In our next report, we will outline proposals for the details of the procedural rules and other aspects of implementing a practical design, as well as the software development that would be necessary.Auctions; Spectrum Auctions; Multiple-Round Auctions; Efficiency

Organizing Production in a Large Economy

We show that in a large production economy, the cost of collecting the information required by a planner to set nearly optimal prices is negligible relative to the total output of the economy. The cost of collecting the information required to set a nearly optimal production plan for each firm in the economy is not negligible. This conclusion stands in contrast to common opinion that determining optimal prices requires as much information as determining an optimal plan.