Durable-Goods Monopolists, Network Effects and Penetration Pricing

We study the pricing problem of a durable-goods monopolist. With network effects, consumption externalities among heterogeneous groups of consumers generate a discontinuous demand function. Consequently, the lessor has to offer a low price in order to reach the mass market, whereas the seller has the option to build a customer base by setting a lower initial price and raise the price later in the mass market, which explains the practice of introductory pricing. Contrary to the existing literature, we show that profits from selling network goods may be higher than from leasing. Further, the seller in fact over-invests in R&D and makes the product more durable than necessary.Penetration pricing, network externality

The Optimal Decoupled Liabilities: A General Analysis

The “decoupled” liability system awards the plaintiff an amount that differs from what the defendant pays. The previous approach to the optimal decoupling design is based on the assumption of complete information, which results in an optimal liability for the defendant “as much as he can afford.” This extreme conclusion may hinder the acceptability of the decoupling system. This paper proposes an alternative design based on the assumption that agents in the post-accident subgame have asymmetric information. Our model indicates that the optimal penalty faced by the defendant is generally greater than the optimal award to the plaintiff. When the potential harm is sufficiently large, the optimal penalty can be approximated by a multiple of the harm, but the plaintiff receives only a finite amount of the damages regardless of the loss suffered. Such a decoupling scheme deters frivolous lawsuits without reducing the defendants’ incentives to exercise care. Additionally, this paper derives comparative static results concerning how the trial costs of the plaintiff and defendant affect the optimal design of decoupling.

The Evolutionary Theory of Time Preferences and Intergenerational Transfers

At each age an organism produces energy by foraging and allocates this energy among reproduction, survival, growth, and intergenerational transfers. We characterize the optimal set of allocation decisions that maximizes reproductive fitness. Time preference (the discount rate) is derived from the marginal rate of substitution between energy obtained at two different times or ages in an individual’s life, holding reproductive fitness constant. We show that the life history may have an initial immature phase during which there is body growth but no fertility, and a later mature phase with fertility but no growth, as with humans. During the immature phase, time preference depends only on the compounding effect of body growth, much like returns on a capital investment, but not on fertility, or the intrinsic population growth rate. During the mature phase, time preference depends on the costliness of fertility, and on endogenous survival and intrinsic growth rate, and not at all on body growth. During the transition between the two phases, fertility, mortality, body growth, and intrinsic growth rate all matter. Using these results, we conclude that time preference and discount rates are likely to be U-shaped across age. We compare our results to Hansson and Stuart (1990), Rogers (1994, 1997) and Sozou and Seymour (2003). Wastage and inefficiencies aside, in a single sex model a system of intergenerational transfers yields Samuelson’s (1958) biological interest rate equal to the population growth rate. When the rate of time preference exceeds this biological rate, inter- generational transfers will raise fitness and evolve through natural selection, partially smoothing out the age variations in time preference.

Gene Context Analysis in the Integrated Microbial Genomes (IMG) Data Management System

Computational methods for determining the function of genes in newly sequenced genomes have been traditionally based on sequence similarity to genes whose function has been identified experimentally. Function prediction methods can be extended using gene context analysis approaches such as examining the conservation of chromosomal gene clusters, gene fusion events and co-occurrence profiles across genomes. Context analysis is based on the observation that functionally related genes are often having similar gene context and relies on the identification of such events across phylogenetically diverse collection of genomes. We have used the data management system of the Integrated Microbial Genomes (IMG) as the framework to implement and explore the power of gene context analysis methods because it provides one of the largest available genome integrations. Visualization and search tools to facilitate gene context analysis have been developed and applied across all publicly available archaeal and bacterial genomes in IMG. These computations are now maintained as part of IMG's regular genome content update cycle. IMG is available at: http://img.jgi.doe.gov

1-De­oxy-d-arabinitol

Addition of methyl lithium to d-erythrono-1,4-lactone followed by acid deprotection was shown, by X-ray crystallography, to give 1-de­oxy-d-arabinitol, C5H12O4, rather than 1-de­oxy-d-ribitol as the major product. The crystal structure exists as hydrogen-bonded chains of mol­ecules running parallel to the c axis which are further linked together by hydrogen bonds. Each mol­ecule is a donor and an acceptor for four hydrogen bonds

A Dynamic Ontology Mapping Architecture for a Grid Database System

Abstract — Most large-scale heterogeneous distributed computing systems, such as Grids, rely on Service Oriented Architectures (SOA) to interact with others in different platforms and computing languages. However, we still need to solve the semantic heterogeneity problem of data; we must interpret the data from different systems in some semantically related ways. Ontologies are the most common and well-accepted methodology to handle this problem at multiple levels of granularities across different systems. Nevertheless, using ontologies in a dynamic environment, such as a Grid, to share some common concepts is still a challenge. It is difficult to keep a static mapping between ontologies; the corresponding semantic mapping changes must occur consistently. Therefore, we adopt the concept of Tuple Space and propose a flexible approach for managing ontologies in a Grid. It enables systems and users to interoperate semantically and dynamically by sharing and managing the concepts and semantic ontology mappings in a flexible approach. I

IMG/M: the integrated metagenome data management and comparative analysis system

The integrated microbial genomes and metagenomes (IMG/M) system provides support for comparative analysis of microbial community aggregate genomes (metagenomes) in a comprehensive integrated context. IMG/M integrates metagenome data sets with isolate microbial genomes from the IMG system. IMG/M’s data content and analytical capabilities have been extended through regular updates since its first release in 2007. IMG/M is available at http://img.jgi.doe.gov/m. A companion IMG/M systems provide support for annotation and expert review of unpublished metagenomic data sets (IMG/M ER: http://img.jgi.doe.gov/mer)

Deep Charging Evaluation of Satellite Power and Communication System Components

No abstract availabl