3,502 research outputs found
Sharing, Gift-Giving, and Optimal Resource Use Incentives in Hunter-Gatherer Society
In the typical hunter-gatherer society, decision-making is collective, yet decentralized, access to resources is shared, goods are typically distributed via reciprocal exchange, sharing, and gift-giving, and the distribution of both income and decision-making power is egalitarian. We argue these features are interrelated. We adopt an incentive-based view of sharing and gift-giving, in which the fundamental role of sharing and gift-giving is to implement socially desirable production decisions in the face of a common resource use problem. We show how this system decentralizes decision-making, while at the same time encouraging agents to make production decisions in the best interests of the group. Sharing rules give agents optimal use incentives, while gift-giving obligations give agents incentives to reveal private information about skill. The system has some interesting properties; for example, it may result in a relatively equal distribution of income, even though the productive capabilities of agents differ. Our theory is also able to account for some features of the ethnographic record that do not jibe well with existing theories of sharing; for example, why the rather extensive free-riding on the efforts of the most productive agents is typically tolerated in hunter-gatherer society.
Probing The Lower Mass Limit For Supernova Progenitors And The High-Mass End Of The Initial-Final Mass Relation From White Dwarfs In The Open Cluster M35 (NGC 2168)
We present a photometric and spectroscopic study of the white dwarf (WD) population of the populous, intermediate-age open cluster M35 (NGC 2168); this study expands upon our previous study of the WDs in this cluster. We spectroscopically confirm 14 WDs in the field of the cluster: 12 DAs, 1 hot DQ, and 1 db star. For each DA, we determine the WD mass and cooling age, from which we derive each star's progenitor mass. These data are then added to the empirical initial-final mass relation (IFMR), where the M35 WDs contribute significantly to the high-mass end of the relation. The resulting points are consistent with previously published linear fits to the IFMR, modulo moderate systematics introduced by the uncertainty in the star cluster age. Based on this cluster alone, the observational lower limit on the maximum mass of WD progenitors is found to be similar to 5.1M(circle dot) - 5.2M(circle dot) at the 95% confidence level; including data from other young open clusters raises this limit to as high as 7.1M(circle dot), depending on the cluster membership of three massive WDs and the core composition of the most massive WDs. We find that the apparent distance modulus and extinction derived solely from the cluster WDs ((m-M)(V) = 10.45 +/- 0.08 and E(B-V) = 0.185 +/- 0.010, respectively) is fully consistent with that derived from main-sequence fitting techniques. Four M35 WDs may be massive enough to have oxygen - neon cores; the assumed core composition does not significantly affect the empirical IFMR. Finally, the two non-DA WDs in M35 are photometrically consistent with cluster membership; further analysis is required to determine their memberships.NSF AST-0397492, AST-0602288Astronom
Process and assembly plans for low cost commercial fuselage structure
Cost and weight reduction for a composite structure is a result of selecting design concepts that can be built using efficient low cost manufacturing and assembly processes. Since design and manufacturing are inherently cost dependent, concurrent engineering in the form of a Design-Build Team (DBT) is essential for low cost designs. Detailed cost analysis from DBT designs and hardware verification must be performed to identify the cost drivers and relationships between design and manufacturing processes. Results from the global evaluation are used to quantitatively rank design, identify cost centers for higher ranking design concepts, define and prioritize a list of technical/economic issues and barriers, and identify parameters that control concept response. These results are then used for final design optimization
Social Position and Distributive Justice: Experimental Evidence
Using a simple, double-blind dictator experiment, we examine the extent to which subjects\u27 choices of distributive shares are influenced by unearned social position. We measure social position by the initial distributive shares (resources) and the subjects\u27 ability to determine the final distributive shares (power). We find that subjects\u27 decisions are consistent with Rawls\u27 (1971) hypothesis that individuals expect a greater share when in a position with more power and initial resources. Finally, we test if subjects\u27 choices under a laboratory veil of ignorance are consistent with Rawls\u27 concept of distributive justice. Veiled individuals exhibit preferences that are less risk-averse and have greater variance than Rawls hypothesized. [excerpt
An Experimental Study of the Holdout Problem in a Multilateral Bargaining Game
When an economic exchange requires agreement by multiple independent parties, the potential exists for an individual to strategically delay agreement in an attempt to capture a greater share of the surplus created by the exchange. This holdout problem is a common feature of the land-assembly literature because development frequently requires the assembly of multiple parcels of land. We use experimental methods to examine holdout behavior in a laboratory bargaining game that involves multi-person groups, complementary exchanges, and holdout externalities. The results of six treatments that vary the bargaining institution, number of bargaining periods, and cost of delay demonstrate that holdout is common across institutions and is, on average, a payoff-improving strategy for responders. Both proposers and responders take a more aggressive initial bargaining stance in multi-period bargaining treatments relative to single-period treatments, but take a less aggressive bargaining stance when delay is costly. Nearly all exchanges eventually occur in our multi-period treatments, leading to higher overall efficiency relative to the single-period treatments, both with and without delay costs. [excerpt
Playing the Game: Trout Unlimited’s engagement with the U.S. Federal Energy Regulatory Commission (FERC) in advocating dam removal on the Clyde River, VT and the Kennebec River, ME
This paper examines interactions between the non-profit interest group Trout Unlimited (TU) and the Federal Energy Regulatory Commission (FERC) during debates over dam removal. It uses one case study on the Clyde River in Vermont and one on the Kennebec River in Maine, delving into the tactics used by TU and to show how the group’s activities contributed to FERC recommendations for dam removal in both cases.
Bureaucratic Behavior Theory is used as the framework to analyze agency rules, citizen participation, and agency official’s beliefs. Kingdon’s Policy Streams framework supports ancillary investigation into the transformation of private economic environmental groups to professionally-managed, science-based groups exemplified by TU. The dam removal scenario introduces a new formula for groups that act as policy entrepreneurs by assembling knowledge communities and actively seeking to apply their solutions. Other interest groups may be able to use this formula to position themselves for success when engaging federal agencies.No embarg
Characterization Approaches to Place Invariant Sites on SI-Traceable Scales
The effort to understand the Earth's climate system requires a complete integration of remote sensing imager data across time and multiple countries. Such an integration necessarily requires ensuring inter-consistency between multiple sensors to create the data sets needed to understand the climate system. Past efforts at inter-consistency have forced agreement between two sensors using sources that are viewed by both sensors at nearly the same time, and thus tend to be near polar regions over snow and ice. The current work describes a method that would provide an absolute radiometric calibration of a sensor rather than an inter-consistency of a sensor relative to another. The approach also relies on defensible error budgets that eventually provides a cross comparison of sensors without systematic errors. The basis of the technique is a model-based, SI-traceable prediction of at-sensor radiance over selected sites. The predicted radiance would be valid for arbitrary view and illumination angles and for any date of interest that is dominated by clear-sky conditions. The effort effectively works to characterize the sites as sources with known top-of-atmosphere radiance allowing accurate intercomparison of sensor data that without the need for coincident views. Data from the Advanced Spaceborne Thermal Emission and Reflection and Radiometer (ASTER), Enhanced Thematic Mapper Plus (ETM+), and Moderate Resolution Imaging Spectroradiometer (MODIS) are used to demonstrate the difficulties of cross calibration as applied to current sensors. Special attention is given to the differences caused in the cross-comparison of sensors in radiance space as opposed to reflectance space. The radiance comparisons lead to significant differences created by the specific solar model used for each sensor. The paper also proposes methods to mitigate the largest error sources in future systems. The results from these historical intercomparisons provide the basis for a set of recommendations to ensure future SI-traceable cross calibration using future missions such as CLARREO and TRUTHS. The paper describes a proposed approach that relies on model-based, SI-traceable predictions of at-sensor radiance over selected sites. The predicted radiance would be valid for arbitrary view and illumination angles and for any date of interest that is dominated by clear-sky conditions. The basis of the method is highly accurate measurements of at-sensor radiance of sufficient quality to understand the spectral and BRDF characteristics of the site and sufficient historical data to develop an understanding of temporal effects from changing surface and atmospheric conditions
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