Priming of Pop-Out Does not Affect the Shooting Line Illusion

We combined a shooting-line illusion with a visual search pop-out task in an effort to determine whether priming of pop-out was due to acceleratcd processing of visual information in the primed dimension. While the priming effect and the line-motion percept were replicated, the visual search task showed no influence on the perceived direction of line motion. These results indicate that the priming effect does not accelerate early visual processing.National Institutes of Health-National Eye Institute (EY05087, 49620-93-1-0407

On the existence of nonoptimal equilibria in dynamic stochastic economies

Economic development

CAN HYPOTHETICAL, QUESTIONS PREDICT ACTUAL, PARTICIPATION IN PUBLIC PROGRAMS? A FIELD VALIDITY TEST USING A PROVISION POINT MECHANISM

Niagara Mohawk Power Corporation utilized a demand revealing public good mechanism to implement a green electricity program for provision of renewable energy and planting trees. This GreenChoiceTM program provided an opportunity to test the reliability of contingent valuation for predicting actual participation levels. In this study, participation levels predicted by hypothetical open-ended and dichotomous choice questions are compared to a reference level obtained from the actual GreenChoiceTM program. This approach represents an important improvement over past public goods contingent valuation validity tests which have relied on voluntary contribution mechanisms to elicit actual willingness to pay, and thus are likely to overestimate hypothetical bias because of free riding. Yet, even with a demand revealing mechanism and controlling for awareness, hypothetical participation levels obtained from dichotomous choice responses are found to significantly exceed actual contributions. In contrast, open-ended responses predict actual contribution levels, in that hypothetical open-ended responses are not significantly different from actual responses. Calibration of hypothetical responses is also explored.Public Economics, Resource /Energy Economics and Policy,

The Stellar Activity - Rotation Relationship

Using a new catalog of 824 solar and late-type stars with X-ray luminosities and rotation periods we have studied the relationship between rotation and stellar activity. From an unbiased subset of this sample the power law slope of the unsaturated regime, $L_X/L_{bol}\propto Ro^\beta$, is fit as $\beta=-2.70\pm0.13$. This is inconsistent with the canonical $\beta=-2$ slope to a confidence of 5$\sigma$ and argues for an interface-type dynamo. Super-saturation is observed for the fastest rotators in our sample and its parametric dependencies are explored. Significant correlations are found with both the corotation radius and the excess polar updraft, the latter theory being supported by other observations. We also present a new X-ray population synthesis model of the mature stellar component of our Galaxy and use it to reproduce deep observations of a high Galactic latitude field. The model, XStar, can be used to test models of stellar spin-down and dynamo decay, as well as for estimating stellar X-ray contamination rates for non-stellar studies.Comment: 4 pages, 4 figures. To appear in the proceedings of Cool Stars 17: 17th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, AN 334, 1-2, Eds Klaus Strassmeier and Mercedes Lopez-Morale

The impact of baryons on the direct detection of dark matter

The spatial and velocity distributions of dark matter particles in the Milky Way Halo affect the signals expected to be observed in searches for dark matter. Results from direct detection experiments are often analyzed assuming a simple isothermal distribution of dark matter, the Standard Halo Model (SHM). Yet there has been skepticism regarding the validity of this simple model due to the complicated gravitational collapse and merger history of actual galaxies. In this paper we compare the SHM to the results of cosmological hydrodynamical simulations of galaxy formation to investigate whether or not the SHM is a good representation of the true WIMP distribution in the analysis of direct detection data. We examine two Milky Way-like galaxies from the MaGICC cosmological simulations (a) with dark matter only and (b) with baryonic physics included. The inclusion of baryons drives the shape of the DM halo to become more spherical and makes the velocity distribution of dark matter particles less anisotropic especially at large heliocentric velocities, thereby making the SHM a better fit. We also note that we do not find a significant disk-like rotating dark matter component in either of the two galaxy halos with baryons that we examine, suggesting that dark disks are not a generic prediction of cosmological hydrodynamical simulations. We conclude that in the Solar neighborhood, the SHM is in fact a good approximation to the true dark matter distribution in these cosmological simulations (with baryons) which are reasonable representations of the Milky Way, and hence can also be used for the purpose of dark matter direct detection calculations.Comment: Minor changes to match JCAP version. 21 pages, 9 figure

A Dynamic Equilibrium Model of Inflation and Unemployment

A stochastic general equilibrium model is constructed which is capable of examining the covariance properties between inflation and unemployment, both conditioned and unconditioned upon the state of exogenous real and monetary factors. Indivisibilities introduced into agents' labor choice decisions produce unemployment in equilibrium. It is shown that indigenous forces in a competitive economy can result in the traditional negative relationship between inflation and unemployment. The policymaker, while perhaps observing a begatively sloped Phillips curve, actually faces Friedman's positively sloped one.Published in connection with a visit at the IIES

A COMPARISON OF HYPOTHETICAL PHONE AND MAIL CONTINGENT VALUATION RESPONSES FOR GREEN PRICING ELECTRICITY PROGRAMS

To date, much of the policy and research debate on contingent valuation mode effects has relied on experiences drawn from other research disciplines. This study provides the first contingent valuation phone-mail comparison that meets current standards for response rates, draws from a general population, is relevant to the valuation of general environmental goods, and allows comparisons with actual sign-ups. Consistent with previous research in other disciplines, social desirability bias is found in responses to subjective questions --thus leading to more environmentally favorable responses on the phone. However, this effect does not carry over to hypothetical participation decisions. Hypothetical bias is found in both modes. Yet, application of calibration methods using debriefing questions provided nearly identical values across modes. As such, neither mode appears to dominate from the perspective of providing more valid estimates of actual participation decisions. The selection of survey mode must be based on other criteria.Environmental Economics and Policy,

 Evaluation of the Albedo-induced Radiative Forcing and CO2 Equivalence Savings: A Case Study on Reflective Pavements in Four Selected U.S. Urban Areas

There is a growing interest in developing cool pavement strategies to mitigate pavement’s impact on the global warming in recent years. One of the mitigation strategies is by increasing the solar reflectance (or albedo) of the pavement surface, which directly contributes to global cooling by adjusting radiative forcing and potentially reduces the energy demand in the urban areas. In this paper, the radiative energy budgets in four urban areas are investigated based on the data derived from NASA satellite measurements. The radiative forcing (RF) due to the change of urban surface albedo as a result of reflective pavements is estimated using a simplified engineering model. The carbon dioxide (CO2) equivalence savings are also calculated with reference to the 100-year global warming potential of CO2. Results show that the implementation of reflective pavement has a great potential to reduce global warming. The CO2 reduction is significant in the urban areas but also affects the surrounding regions to some extent. In the end, we recommend using a climate model incorporating site-specific information that enables the visualization of the outputs through spatial maps. The results from this work would be useful for guiding the implementation of the cool pavement strategies.CSHub@MIT is conducted with sponsorship provided by the Portland Cement Association and the Ready Mixed Concrete Research & Education Foundation