A Cost-Index Approach to Valuing Investment In "Far Into The Future" Environmental Technology

Governments investing in long-lead technology development programs face considerable uncertainty as to whether the investment eventually will “pay off” for the taxpayer. This paper offers a framework to inform long-lead technology investment. We extend the theory of quality-adjusted cost indices to develop a conceptually rigorous, but data parsimonious, means of estimating consumer benefits from a new technology. We apply this model to a possible future electricity generation technology, space solar power (SSP). The United States, Japan, and other governments have begun investing in SSP but lack the benefit of a relevant economic context for informed decisions. We frame and analyze the economic relationship between SSP and competing electricity generation technologies with respect to direct costs, environmental externalities, and reliability. We also explicitly incorporate uncertainty and consider differences in the resource endowments available to electricity markets by considering four distinct world geographic regions.energy, environment, technological change, cost indices, space technology

Common Mitochondrial DNA Mutations Generated through DNA-Mediated Charge Transport

Mutation sites that arise in human mitochondrial DNA as a result of oxidation by a rhodium photooxidant have been identified. HeLa cells were incubated with [Rh(phi)2bpy]Cl3 (phi is 9,10-phenanthrenequinone diimine), an intercalating photooxidant, to allow the complex to enter the cell and bind mitochondrial DNA. Photoexcitation of DNA-bound [Rh(phi)2bpy]3+ can promote the oxidation of guanine from a distance through DNA-mediated charge transport. After two rounds of photolysis and growth of cells incubated with the rhodium complex, DNA mutations in a portion of the mitochondrial genome were assessed via manual sequencing. The mutational pattern is consistent with dG to dT transversions in the repetitive guanine tracts. Significantly, the mutational pattern found overlaps oxidative damage hot spots seen previously. These mutations are found within conserved sequence block II, a critical regulatory element involved in DNA replication, and these have been identified as sites of low oxidation potential to which oxidative damage is funneled. On the basis of this mutational analysis and its correspondence to sites of long-range oxidative damage, we infer a critical role for DNA charge transport in generating these mutations and, thus, in regulating mitochondrial DNA replication under oxidative stress

More Than a Wing and a Prayer: Government Indemnification of the Commercial Space Launch Industry

Using rockets to launch communications satellites and other spacecraft poses risks to the uninvolved public, including persons and property under the flight path of the launch vehicle. The federal government plays a pivotal technical role during the actual launch by carrying out certain risk-related procedures, thus causing third-party risk to be jointly produced by the company and the government. In addition, under the Commercial Space Launch Act, the government partially indemnifies commercial launch companies for third-party damages. We compare the indemnification policy to optimal liability rules under public-private co-production of risk. Under modest assumptions, shared liability created by the indemnification rules decreases the incentive of both parties to take care relative to the optimum. If care were observable, it would be preferable for the government to fully indemnify companies that take due care. The role of the government as an agent for third parties may qualify these findings.government indemnification, liability, insurance, space transportation

Spatially and Intertemporally Efficient Waste Management: The Costs of Interstate Flow Control

We examine the intertemporal allocation of the solid waste of cities within the United States to spatially distributed landfills and incinerators, taking into account that capacity at existing and potential landfills is scarce. Amendments have been proposed to restrict waste flows between states by means of quotas and surcharges. We assess the aggregate surplus loss (and its regional distribution) resulting from proposed policies. In addition, we find that limitations on the size of shipments to any one state can have the perverse effect of substantially increasing interstate waste shipments as states export smaller volumes to more destinations.Solid Waste, Efficiency, Hotelling

Examining the Dimensionality and Contributors of Kindergarten Composition

Despite increasing pressure for children to learn to write at younger ages, there are many unanswered questions about composition skills in early elementary school. The goals of this dissertation were to add to knowledge about the measurement of young children’s writing and its component skills. Both studies explore the composition skills of a sample of 282 kindergartners. In Study 1, confirmatory factor analyses indicated that a qualitative scoring system and a productivity scoring system capture distinct dimensions of kindergartners’ compositions. A scoring system for curriculum-based measurement could not attain acceptable fit, which may suggest that CBM is ill-suited for capturing the important components of writing for kindergartners. This study indicated that the measurement and components of composition in kindergarten may be qualitatively different from the compositions of older children. Study 2 addressed two dimensions of kindergarten composition and skills that contribute to them, text generation and transcription. Latent moderated structural equation modeling was used to test the hypothesis that transcription moderates the relation between text generation and composition for kindergarten writers. This hypothesis is one possible manifestation of the Developmental Constraints Hypothesis (DCH). In support of the DCH, transcription had a strong constraining effect on both composition quality and productivity. Additionally, transcription moderates the relation between text generation and composition quality, although the moderation is negative. There is no signification moderation of transcription on the text generation-composition relation