Unemployment with Observable Aggregate Shocks

Consider an economy subject to two kinds of shocks: (a) an observable shock to the relative demand for final goods which causes dispersion in relative prices, and (b) shocks, unobservable by workers, to the technology for transforming intermediate goods into final goods. A worker in a particular intermediate goods industry knows that the unobserved price of his output is determined by (1) the technological shock that determines which final goods industry uses his output intensively and (2) the price of the final good that uses his output intensively. When there is very little relative price dispersion among final goods, then it doesn't matter which final goods industry uses the worker's output. Thus the technological shock is of very little importance in creating uncertainty about the worker's marginal product when there is little dispersion of relative prices. Hence an increase in the dispersion of relative prices amplifies the effect of technological uncertainty on a worker's marginal value product. We consider a model of optimal labor contracts in a situation where the workers have less information than the firm about their marginal value product. A relative price shock of the type described above increases the uncertainty which workers have about their marginal value product. We show that with an optimal asymmetric information employment contract the industries which are adversely affected by the relative price shock will contract more than they would under complete information (i.e., where workers could observe their marginal value product). On the other hand the industry which is favorably affected by the relative price shock will - not expand by more than would be the case under complete information. Hence an observed relative demand shock, which would leave aggregate employment unchanged under complete information, will cause aggregate employment to fall under asymmetric information about the technological shock.

Coastal Resilience for Habitats and Humans: Integrating Green and Grey Infrastructure Solutions

Communities are protected from floods and storms by both engineered infrastructure like levees, and natural habitat infrastructure like wetlands. We understand the performance and cost effectiveness of engineered or grey infrastructure well. However, recent natural disasters have illustrated both their insufficiency in protecting communities and the high repair costs. We know that green infrastructure, or natural habitats, also protect communities from river floods and coastal storms but we know little about their performance and cost. This knowledge gap leads to greater investment in grey at the expense of green. In addition, green infrastructure provide other benefits to human communities, and are often the restoration target of recovery plans for ecosystems and endangered species. In Puget Sound we evaluated the changes in vulnerability for both ecosystems and built infrastructure that may result from climate change, including changes in high and low river flows, sea level, storm dynamics, sediment recruitment and salinity intrusion. We developed an interactive tool called Coastal Resilience that allows users to examine community risk in a way that integrates both green and grey infrastructure. The tool allows users to evaluate different sources of risk, such as “dike freeboard” which indicates how close a dike comes to being overtopped under various current and future storm scenarios. Another tool provides a model that quantifies the reduction in storm wave energy and height that is provided by tidal wetlands which protect adjacent dike systems from erosion and overtopping. In areas where tidal wetlands are receding, it can indicate how community risk and financial cost may change as a result of this loss of protective green infrastructure. With this information, communities can develop better response plans that reduce the costs of disaster prevention and recovery, and increase the economic efficiency of both risk reduction and ecosystem recovery actions

Stress effects on the Raman spectrum of an amorphous material: theory and experiment on a-Si:H

Strain in a material induces shifts in vibrational frequencies, which is a probe of the nature of the vibrations and interatomic potentials, and can be used to map local stress/strain distributions via Raman microscopy. This method is standard for crystalline silicon devices, but due to lack of calibration relations, it has not been applied to amorphous materials such as hydrogenated amorphous silicon (a-Si:H), a widely studied material for thin-film photovoltaic and electronic devices. We calculated the Raman spectrum of a-Si:H \ab initio under different strains $\epsilon$ and found peak shifts $\Delta \omega = \left( -460 \pm 10\ \mathrm{cm}^{-1} \right) {\rm Tr}\ \epsilon$. This proportionality to the trace of the strain is the general form for isotropic amorphous vibrational modes, as we show by symmetry analysis and explicit computation. We also performed Raman measurements under strain and found a consistent coefficient of $-510 \pm 120\ \mathrm{cm}^{-1}$. These results demonstrate that a reliable calibration for the Raman/strain relation can be achieved even for the broad peaks of an amorphous material, with similar accuracy and precision as for crystalline materials.Comment: 12 pages, 3 figures + supplementary 8 pages, 4 figure

Using a design charrette and state of the art coastal modeling to support local government adaptation to sea level rise

The majority of the Town of La Conner sits at an elevation (MLLW) of 8-13 feet where over the last number of years Town staff have gone from seeing the baseboards of their overwater business district being reached once or twice every four to five years to being reached four to five times a year. These high water events come at great expense to the Town and leave the Town regularly just shy of a major disaster. The Town of La Conner partnered with the Skagit Climate Science Consortium (including USGS, UW Climate Impacts Group and Western Washington University) and CollinsWoerman to use state of the art modeling of tides, storm surge and sea level rise coupled with an innovative design charrette approach to begin a conversation with the Planning Commission, Town Council, town residents and business owners. The results of the charrette are now feeding into their Comprehensive Plan update process and will also inform a new Capital Facilities Plan. In addition, the conversations stimulated by the design charrette mark the beginning of forging a new vision for this coastal town by its inhabitants. Town leadership and others are turning away from the current paradigm of resistance and leaning into accepting seas. With this new thinking they are exploring how to accommodate these kinds of changes more creatively and with less environmental impact. Thus, the La Conner Design Charrette model and the new scientific information utilized can serve as an example for how others in the Salish Sea can approach understanding coastal changes and create constructive conversations about adaptation in a rapidly changing world

A Multi-Level Fit-Based Quality Improvement Initiative to Improve Colorectal Cancer Screening in a Managed Care Population.

IntroductionColorectal cancer (CRC) is a common but largely preventable disease with suboptimal screening rates despite national guidelines to screen individuals age 50-75. Single-component interventions aimed to improve screening uptake only modestly improve rates; data suggest that multi-modal approaches may be more effective.MethodsWe designed, implemented, and evaluated the impact of a multi-modal intervention on CRC screening uptake among unscreened patients in a large managed care population. Patient-level components included a mailed letter with education about screening options and pre-colonoscopy telephone counseling. For providers, we facilitated communication of screening test results and work-flow for abnormal results. System-level modifications included establishment of a patient navigator, expedited work-up for abnormal results, and stream-lined colonoscopy scheduling. We measured the rate of screening uptake overall, screening uptake by modality, change in the proportion of the population screened, and positive fecal immunochemical test (FIT) follow-up rates in the 1-year study period.ResultsThere were 5093 patients in the intervention cohort. Of these, 33.2% participated in FIT or colonoscopy screening within 1 year of the mailing. A total of 1078 (21.2%) participants completed a FIT and 611 (12.0%) completed a screening colonoscopy. The screening rate in the managed care population increased from 65.1 to 76.6%. Fifty-nine patients (5.5%) had a positive FIT, of which 30 (50.8%) completed a diagnostic colonoscopy.ConclusionMulti-modal interventions can result in substantial improvement in CRC screening uptake in large and diverse managed care populations.Translational impactHealth systems should shift their focus from single-level to multi-level interventions when addressing barriers to CRC screening

Unemployment with Observable Aggregate Shocks

A general equilibrium model of' optimal employment contracts is developed where firms have better information about labor's marginal product than workers. It is optimal for the wage to be tied to the level of employment, to prevent the firm from falsely stating that the marginal product is low and cutting the wage. It is shown that an observed aggregate shock that leads to an interindustry shift in labor demand and that would have no effect on total employment under symmetric information leads to a reduction in employment when firms and workers have asymmetric information.Economic

El Nino Influence on Holocene Reef Accretion in Hawai'i

New observations of reef accretion from several locations show that in Hawai'i accretion during early to middle Holocene time occurred in areas where today it is precluded by the wave regime, suggesting an increase in wave energy. Accretion of coral and coralline algae reefs in the Hawaiian Islands today is largely controlled by wave energy. Many coastal areas in the main Hawaiian Islands are periodically exposed to large waves, in particular from North Pacific swell and hurricanes. These are of sufficient intensity to prevent modern net accretion as evidenced by the antecedent nature of the seafloor. Only in areas sheltered from intense wave energy is active accretion observed. Analysis of reef cores reveals patterns of rapid early Holocene accretion in several locations that terminated by middle Holocene time, ca. 5000 yr ago. Previous analyses have suggested that changes in Holocene accretion were a result of reef growth "catching up" to sea level. New data and interpretations indicate that the end of reef accretion in the middle Holocene may be influenced by factors in addition to sea level. Reef accretion histories from the islands of Kaua'i, O'ahu, and Moloka'i may be interpreted to suggest that a change in wave energy contributed to the reduction or termination of Holocene accretion by 5000 yr ago in some areas. In these cases, the decrease in reef accretion occurred before the best estimates of the decrease in relative sea-level rise during the mid-Holocene high stand of sea level in the main Hawaiian Islands. However, reef accretion should decrease following the termination of relative sea-level rise (ca. 3000 yr ago) if reef growth were "catching up" to sea level. Evidence indicates that rapid accretion occurred at these sites in early Holocene time and that no permanent accretion is occurring at these sites today. This pattern persists despite the availability of hard substrate suitable for colonization at a wide range of depths between -30 m and the intertidal zone. We infer that forcing other than relative sea-level rise has altered the natural ability to support reef accretion on Hawaiian insular shelves. The limiting factor in these areas today is wave energy. Numbers of both large North Pacific swell events and hurricanes in Hawai'i are greater during El Nino years. We infer that if these major reef-limiting forces were suppressed, net accretion would occur in some areas in Hawai'i that are now wave-limited. Studies have shown that El Nino/Southern Oscillation (ENSO) was significantly weakened during early-mid Holocene time, only attaining an intensity similar to the current one ca. 5000 yr ago. We speculate that this shift in ENSO may assist in explaining patterns of Holocene Hawaiian reef accretion that are different from those of the present and apparently not related to relative sea-level rise

Hole-mobility-limiting atomic structures in hydrogenated amorphous silicon

Low hole mobility currently limits the efficiency of amorphous silicon photovoltaic devices. We explore three possible phenomena contributing to this low mobility: coordination defects, self-trapping ionization displacement defects, and lattice expansion allowing for hole wave-function delocalization. Through a confluence of experimental and first-principles investigations, we demonstrate the fluidity of the relative prevalence of these defects as film stress and hydrogen content are modified, and that the mobility of a film is governed by an interplay between various defect types