The Timing of Purchases, Market Power, and Economic Fluctuations.

This paper analyzes a market in which sellers have power market and set price taking into account the ability of buyers to time their purchases. I demonstrate that expected fluctuations in demand are inherently fluctuations in the elasticity of demand, leading to smaller markups on the up-side of booms.PRICING ; DEMAND ; FLUCTUATIONS

A Vintage Capacity Model of Production

In recent years, many econometric studies of production processes have been undertaken at both the industry and aggregate levels. Such studies represent an attempt to use aggregated, observable data on prices and flows of industry inputs and outputs to estimate important characteristics of production technology such as elasticities of substitution between inputs to production. Many studies have been based on an assumption of continuous minimum-cost equilibrium and make no distinction between short- and long-run effects. Such an assumption can lead to a fundamental misspecification of the model and biased estimates of substitution elasticities. As an alternative to this static equilibrium model, a vintage model is developed here which embodies a polar opposite assumption about production technology -- that once production units have been installed, their technologies are fixed. This assumption corresponds more closely to the nature of production in some sectors of the economy. The structure of the vintage capacity model is such that it can be estimated using data and econometric techniques almost identical to those used for the static equilibrium model. This suggests the feasibility of using both models to generate alternative estimates of important parameters of production technology. In Section II of this paper, the structure of the static equilibrium model is briefly reviewed and its common features with the vintage capacity model are noted. In Section III, the vintage capacity model is presented, highlighting the differences between the two models. The conclusion discusses possible implementations of the model and ways in which the model could be extended

Risk management for drinking water safety in low and middle income countries: cultural influences on water safety plan (WSP) implementation in urban water utilities

We investigated cultural influences on the implementation of water safety plans (WSPs) using case studies from WSP pilots in India, Uganda and Jamaica. A comprehensive thematic analysis of semi-structured interviews (n = 150 utility customers, n = 32 WSP ‘implementers’ and n = 9 WSP ‘promoters’), field observations and related documents revealed 12 cultural themes, offered as ‘enabling’, ‘limiting’, or ‘neutral’, that influence WSP implementation in urban water utilities to varying extents. Aspects such as a ‘deliver first, safety later’ mind set; supply system knowledge management and storage practices; and non-compliance are deemed influential. Emergent themes of cultural influence (ET1 to ET12) are discussed by reference to the risk management, development studies and institutional culture literatures; by reference to their positive, negative or neutral influence on WSP implementation. The results have implications for the utility endorsement of WSPs, for the impact of organisational cultures on WSP implementation; for the scale-up of pilot studies; and they support repeated calls from practitioner communities for cultural attentiveness during WSP design. Findings on organisational cultures mirror those from utilities in higher income nations implementing WSPs – leadership, advocacy among promoters and customers (not just implementers) and purposeful knowledge management are critical to WSP success

Consumption Over the Life Cycle.

This paper employs a synthetic cohort technique and Consumer Expenditure Survey data to construct average age-profiles of consumption and income over the working lives of typical households across different education and occupation groups.CONSUMPTION ; INCOME

(2+1) Resonance Enhanced Ionization Spectroscopy of a State Selected Beam of OH Radicals

A state-selected beam of hydroxyl radicals is generated using a pulsed discharge source and hexapole field. The OH radicals are characterized by resonance-enhanced multiphoton ionization (REMPI) spectroscopy via the nested D  and 3  Rydberg states. Simplified spectra are observed from the selected ∣MJ∣ = 3/2 component of the upper Λ-doublet level of the lowest rotational state (J = 3/2) in ground (v″ = 0) and excited(v″ = 1–3) vibrational levels of the OH X  state. Two-photon transitions are observed to the D (v′ = 0–3) and 3 (v′ = 0,1) vibronic levels, extending previous studies to higher vibrational levels of the Rydberg states. Spectroscopic constants are derived for the Rydberg states and compared with prior experimental studies. Complementary first-principle theoretical studies of the D  and 3  Rydberg states [see M. P. J. van der Loo and G. C. Groenenboom, J. Chem. Phys. 123, 074310 (2005), following paper ] are used to interpret the experimental findings and examine the utility of the (2+1) REMPI scheme for sensitive detection of OH radicals

Editorial: Understanding persistent postoperative pain in South Africa

No Abstrac

Conscientiousness and perceived ethicality: Examining why hierarchy of authority diminishes this positive relationship

Human resource (HR) managers hire conscientious employees because they are both productive and are viewed as upholding high ethical standards due to their propensity to engage in voice. Organizations may strive to create a work context conducive to all employees acting ethically, not just conscientious ones, by centralizing decision-making authority and promoting formalization through a higher hierarchy of authority. Yet, we propose that from the social information processing perspective, in higher hierarchy of authority contexts, peers may view their highly conscientious colleagues as less ethical. We hypothesize these effects through the lens of trait activation theory, according to which in a higher hierarchy of authority context, others are less likely to notice the voice behaviors of conscientious employees. Problematically, when others fail to notice conscientious employees' voice, they may perceive these workers as being less ethical. We tested our hypothesized moderated mediation model in a matched sample of employees (N = 820), their supervisors (N = 445), and peers (N = 529). As predicted, hierarchy of authority moderated the positive relationship between conscientiousness and voice, which in turn explained others' perceptions of their ethicality. Conscientiousness was positively related to peer assessments of ethicality via promotive (not prohibitive) voice when hierarchy of authority was lower (but not higher), partially supporting our hypotheses. These results suggest HR practitioners should be cognizant of the differential evaluations of highly conscientious employees in contexts with different levels of hierarchy of authority, and continuing challenges associated with balancing flexibility and formalization

Acceleration of the universe, vacuum metamorphosis, and the large-time asymptotic form of the heat kernel

We investigate the possibility that the late acceleration observed in the rate of expansion of the universe is due to vacuum quantum effects arising in curved spacetime. The theoretical basis of the vacuum cold dark matter (VCDM), or vacuum metamorphosis, cosmological model of Parker and Raval is revisited and improved. We show, by means of a manifestly nonperturbative approach, how the infrared behavior of the propagator (related to the large-time asymptotic form of the heat kernel) of a free scalar field in curved spacetime causes the vacuum expectation value of its energy-momentum tensor to exhibit a resonance effect when the scalar curvature R of the spacetime reaches a particular value related to the mass of the field. we show that the back reaction caused by this resonance drives the universe through a transition to an accelerating expansion phase, very much in the same way as originally proposed by Parker and Raval. Our analysis includes higher derivatives that were neglected in the earlier analysis, and takes into account the possible runaway solutions that can follow from these higher-derivative terms. We find that the runaway solutions do not occur if the universe was described by the usual classical FRW solution prior to the growth of vacuum energy-density and negative pressure (i.e., vacuum metamorphosis) that causes the transition to an accelerating expansion of the universe in this theory.Comment: 33 pages, 3 figures. Submitted to Physical Review D15 (Dec 23, 2003). v2: 1 reference added. No other change