When does aggregation reduce uncertainty aversion?

We study the problem of uncertainty sharing within a household: "risk sharing," in a context of Knightian uncertainty. A household shares uncertain prospects using a social welfare function. We characterize the social welfare functions such that the household is collectively less averse to uncertainty than each member, and satises the Pareto principle and an independence axiom. We single out the sum of certainty equivalents as the unique member of this family which provides quasiconcave rankings over risk-free allocations

Supermodularity and preferences

We uncover the complete ordinal implications of supermodularity on finite lattices under the assumption of weak monotonicity. In this environment, we show that supermodularity is ordinally equivalent to the notion of quasisupermodularity introduced by Milgrom and Shannon. We conclude that supermodularity is a weak property, in the sense that many preferences have a supermodular representation

Ordinal notions of submodularity

We consider several ordinal formulations of submodularity, defined for arbitrary binary relations on lattices. Two of these formulations are essentially due to Kreps [Kreps, D.M., 1979. A representation theorem for “Preference for Flexibility”. Econometrica 47 (3), 565–578] and one is a weakening of a notion due to Milgrom and Shannon [Milgrom, P., Shannon, C., 1994. Monotone comparative statics. Econometrica 62 (1), 157–180]. We show that any reflexive binary relation satisfying either of Kreps’s definitions also satisfies Milgrom and Shannon’s definition, and that any transitive and monotonic binary relation satisfying the Milgrom and Shannon’s condition satisfies both of Kreps’s conditions

Profit maximization and supermodular technology

A dataset is a list of observed factor inputs and prices for a technology; profits and production levels are unobserved. We obtain necessary and sufficient conditions for a dataset to be consistent with profit maximization under a monotone and concave revenue based on the notion of cyclic monotonicity. Our result implies that monotonicity and concavity cannot be tested, and that one cannot decide if a firm is competitive based on factor demands. We also introduce a condition, cyclic supermodularity, which is both necessary and sufficient for data to be consistent with a supermodular technology. Cyclic supermodularity provides a test for complementarity of production factors

On behavioral complementarity and its implications

We study the behavioral definition of complementary goods: if the price of one good increases, demand for a complementary good must decrease. We obtain its full implications for observable demand behavior (its testable implications), and for the consumer's underlying preferences. We characterize those data sets which can be generated by rational preferences exhibiting complementarities. The class of preferences that generate demand complements has Leontief and Cobb–Douglas as its as extreme members

Inefficiency

We introduce an ordinal model of efficiency measurement. Our primitive is a notion of efficiency that is comparative, but not cardinal or absolute. In this framework, we postulate axioms that we believe an ordinal efficiency measure should satisfy. Primary among these are choice consistency and planning consistency, which guide the measurement of efficiency in a firm with access to multiple technologies. Other axioms include symmetry, which states that the names of commodities do not matter, scale-invariance, which says that units of measurement of commodities does not matter, and strong monotonicity, which states that efficiency should decrease if the inputs and outputs remain static when the technology becomes unambiguously more efficient. These axioms characterize a unique ordinal efficiency measure which is represented by the coefficient of resource utilization. By replacing symmetry (the weakest of our axioms) with a very mild continuity condition, we obtain a family of path-based measures.Efficiency Measurement, Coefficient of Resource Utilization, Ordinal, Choice Consistency, Planning Consistency, Path-based

Spherical Preferences

We introduce and study the property of orthogonal independence, a restricted additivity axiom applying when alternatives are orthogonal. The axiom requires that the preference for one marginal change over another should be maintained after each marginal change has been shifted in a direction that is orthogonal to both. We show that continuous preferences satisfy orthogonal independence if and only if they are spherical: their indifference curves are spheres with the same center, with preference being "monotone" either away or towards the center. Spherical preferences include linear preferences as a special (limiting) case. We discuss different applications to economic and political environments. Our result delivers Euclidean preferences in models of spatial voting, quadratic welfare aggregation in social choice, and expected utility in models of choice under uncertainty

On Behavioral Complementarity and its Implications

We study the behavioral denition of complementary goods: if the price of one good increases, demand for a complementary good must decrease. We obtain its full implications for observable demand behavior (its testable implications), and for the consumer's underlying preferences. We characterize those data sets which can be generated by rational preferences exhibiting complementarities. In a model in which income results from selling an endowment (as in general equilibrium models of exchange economies), the notion is surprisingly strong and is essentially equivalent to Leontief preferences. In the model of nominal income, the notion describes a class of preferences whose extreme cases are Leontief and Cobb-Douglas respectively.Afriat's Theorem, Weak Axiom of Revealed Preference, Complementary goods.

Training healthcare assistants working in adult acute inpatient wards in Psychological First Aid: An implementation and evaluation study.

WHAT IS KNOWN ON THE SUBJECT: Healthcare assistants are untrained and unregistered frontline staff but are expected to be proactive in preventing and responding to 'untoward' incidents quickly and efficiently when working within adult acute inpatient psychiatric settings. Healthcare assistants should be trained to provide enhanced care to service users residing in acute psychiatric settings. To date, a training programme in Psychological First Aid has not been expended in such a setting with nonregistered staff. WHAT THE PAPER ADDS TO EXISTING KNOWLEDGE: The study demonstrates that training healthcare assistants in Psychological First Aid is useful in improving their confidence in caring for service users, therapeutic engagement with service users and ward culture in general. WHAT ARE THE IMPLICATIONS FOR PRACTICE: A training programme in Psychological First Aid for healthcare assistants to enhance ward culture can be implemented in different practice environments. Psychological First Aid is harmonious with nursing values and provides healthcare assistants with a relevant, useful and easily understood toolkit to apply in acute psychiatric settings. ABSTRACT: Introduction Healthcare assistants working within adult acute inpatient psychiatric settings are untrained and unregistered, however, they can contribute to quality service if they receive some training. Psychological First Aid training has never been expended in these settings, so this study intends to fill this gap in the existing evidence with this category of healthcare personnel. Aim The aim of this study was to introduce and evaluate first aid training for healthcare assistants. Method A pre/post design was adopted to gather data using questionnaires and interviews. The groups of participants included 16 healthcare assistants trained in Psychological First Aid, a sample of service users and four ward managers. Results Post-training, (a) healthcare assistants and service users ranked the therapeutic milieu of the ward more favourably, (b) the self-efficacy of the healthcare assistants increased, and the number of 'untoward' incidents decreased, and (c) health care assistants' confidence in their skills was high. The ward manager interviews post-training revealed four themes: (a) staff utilization of new skills and renewed enthusiasm, (b) calmer atmosphere on the ward and staff togetherness, (c) confidence and reflection on practice and (d) therapeutic engagement. Discussion Training healthcare assistants is useful in improving staff confidence, therapeutic engagement with service users and ward culture in general. Implications for practice Techniques and skills learnt are relevant and useful to healthcare assistants and provide an easily understood toolkit that is harmonious with nursing values. If executed correctly, the training can enhance practice and care outcomes and the overall service user experience

Wind-Tunnel Investigation of an Advanced General Aviation Canard Configuration

Wind-tunnel tests of a model of an advanced canard configuration designed for general aviation were conducted in the Langley 30- by 60-Foot Tunnel. The objective of the tests was to determine the aerodynamic stability and control characteristics of the configuration for a large range of angles of attack and sideslip at several power conditions. Analysis of the aerodynamic data indicates significant effects of power and of center-of-gravity location. For forward center-of-gravity locations, the configuration had extremely stall-resistant stability and control characteristics. For aft center-of-gravity locations and high-power conditions, the combined effects of increased pitch control and reduced longitudinal stability overpowered the stall resistance provided by the canard, which led to a high-angle-of-attack, deep-stall trim condition. Other aspects of the aerodynamic characteristics studied include the following: flow-visualization study, effect of negative angles of attack, lateral-directional characteristics, and comparison of the stall characteristics with another canard configuration