10,322 research outputs found

    A non-parametric bound on substitution bias in the UK retail prices index

    Get PDF
    This paper uses revealed preference restrictions and nonparametric statistical methods to bound true cost-of-living indices. These are compared to the popular price indices including the type used to calculated the UK RPI. This is used to assess the method of calculating the RPI for substitution bias

    Valuing quality

    Get PDF
    This paper uses revealed preference restrictions and nonparametric statistical methods to bound a quality-constant price series for a good that changes quality over time. Unlike the more usual hedonic regression techniques for estimating quality-adjusted prices, this method does not require us to observe the changing characteristics of the good or to assume a particular functional relationship between these characteristics and quality. To place a bound on quality change using revealed preference conditions we assume that preferences are stable over time, that quality change occurs in one good or group of goods and that the direction of quality change is known

    Nonparametric methods for the characteristic model

    Get PDF
    Characteristics models have been found to be useful in many areas of economics. However, their empirical implementation tends to rely heavily on functional form assumptions. In this paper we develop a revealed preference-based nonparametric approach to characteristics models. We derive the minimal necessary and sufficient empirical conditions under which data on the market behaviour of individual, heterogeneous, pricetaking consumers are nonparametrically consistent with the consumer characteristics model. Where these conditions hold, we show how information may be recovered on individual consumer’s marginal valuations of product attributes. In some cases marginal valuations are point identified and in other cases we can only recover bounds. Where the conditions fail we highlight the role which the introduction of unobserved product attributes can play in rationalising the data. We implement these ideas using consumer panel data on the Danish milk market

    Reference manual for the Langley Research Center flight simulation computing system

    Get PDF
    The researchers at the Langley Research Center Flight Simulation Computing System are provided with an advanced real-time digital simulation capability. This capability is controlled at the user interface level by the Real Time Simulation Supervisor. The Supervisor is a group of subprograms loaded with a simulation application program. The Supervisor provides the interface between the application program and the operating system, and coordinates input and output to and from the simulation hardware. The Supervisor also performs various utility functions as required by a simulation application program

    A randomized trial of brief intervention strategies in patients with alcohol-related facial trauma as a result of interpersonal violence

    Get PDF
    Facial trauma is associated with male gender, low socioeconomic status, alcohol misuse, and violence. Brief intervention (BI) for alcohol is effective at reducing consumption in patients presenting with facial trauma. Singlesession control of violence for angry impulsive drinkers(SS-COVAID) is a new intervention that attempts to address alcohol-related violence. This study assessed the effect of SS-COVAID and BI on drinking and aggression in facial trauma patients. Male facial trauma patients who sustained their injuries as a result of interpersonal violence while drinking and who had Alcohol Use Disorders Identification Test (AUDIT) scores of ≥8 were randomized to either BI or SS-COVAID. Patients were followed up at six and 12 months, and drinking and aggression outcomes were analyzed. One hundred ninety-nine patients entered the trial, and 187 were included in the analysis. Of these, 165 (89%) considered themselves to be victims, 92 (51%) had sustained a previous alcohol-related injury, and 28 (15%) had previous convictions for violence. Both interventions resulted in a significant decrease in negative drinking outcomes over 12 months of follow-up (p<0.001). Neither intervention had a significant effect on aggression scores, nor was there a significant difference between interventions in terms of either outcome. Both SS-COVAID and BI had a significant effect on drinking variables in this patient cohort. No effect on aggressionwas seen despite the fact that SS-COVAID specifically addresses the relationship between alcohol and violence. One reason for this may be that the facial trauma patients in this study considered themselves to be victims rather than aggressors. Another possibility is that, while BI may successfully address lifestyle factors such as hazardous or harmful drinking, it may not be effective in modifying personality traits such as aggression

    Multifrequency Radio Observations of a SNR in the LMC. The Case of SNR J0527-6549 (DEM l204)

    Full text link
    We present a detailed study and results of new Australia Telescope Compact Array (ATCA) observations of supernova remnant, SNR J0527-6549. This Large Magellanic Cloud (LMC) ob ject follows a typical supernova remnant (SNR) horseshoe morphology with a diameter of D=(66x58)+-1 pc which is among the largest SNRs in the LMC. Its relatively large size indicates older age while a steeper than expected radio spectral index of aplha=-0.92+-0.11 is more typical for younger and energetic SNRs. Also, we report detections of regions with a high order of polarization at a peak value of ~54+-17% at 6 cm.Comment: 9 Pages, 6 figures, accepted for publication in SA

    High-Resolution Observations of Interstellar Ca I Absorption -- Implications for Depletions and Electron Densities in Diffuse Clouds

    Get PDF
    We present high-resolution (FWHM ~ 0.3-1.5 km/s) spectra of interstellar Ca I absorption toward 30 Galactic stars. Comparisons of the column densities of Ca I, Ca II, K I, and other species -- for individual components identified in the line profiles and also when integrated over entire lines of sight -- yield information on relative electron densities and depletions. There is no obvious relationship between the ratio N(Ca I)/N(Ca II) [equal to n_e/(Gamma/alpha_r) for photoionization equilibrium] and the fraction of hydrogen in molecular form f(H2) (often taken to be indicative of the local density n_H). For a smaller sample of sightlines for which the thermal pressure (n_H T) and local density can be estimated via analysis of the C I fine-structure excitation, the average electron density inferred from C, Na, and K (assuming photoionization equilibrium) seems to be independent of n_H and n_H T. While the n_e obtained from the ratio N(Ca I)/N(Ca II) is often significantly higher than the values derived from other elements, the patterns of relative n_e derived from different elements show both similarities and differences for different lines of sight -- suggesting that additional processes besides photoionization and radiative recombination commonly and significantly affect the ionization balance of heavy elements in diffuse IS clouds. Such additional processes may also contribute to the (apparently) larger than expected fractional ionizations (n_e/n_H) found for some lines of sight with independent determinations of n_H. In general, inclusion of ``grain-assisted'' recombination does reduce the inferred n_e, but it does not reconcile the n_e estimated from different elements. The depletion of calcium may have a much weaker dependence on density than was suggested by earlier comparisons with CH and CN.Comment: aastex, 70 pages, accepted to ApJ

    A non-parametric bound on substitution bias in the UK retail prices index

    Get PDF
    This paper uses revealed preference restrictions and nonparametric statistical methods to bound true cost-of-living indices. These are compared to the popular price indices including the type used to calculated the UK RPI. This is used to assess the method of calculating the RPI for substitution bias

    Breeding behavior and pup development of the Caspian seal, Pusa caspica

    Get PDF
    The Caspian seal, Pusa caspica, is an ice-breeding phocid endemic to the Caspian Sea. The breeding behavior of this species is poorly documented. Here, we report behavioral observations of 518 mother-pup pairs and 210 lone pups, made from the bridge of icebreakers traversing seal breeding grounds while servicing oil installations in the northeastern Caspian Sea, during 34 trips from late January to early March, 2006-2012. The breeding habitat of Caspian seals is land-fast or drift ice, usually at least 20 cm thick, overlying water 3–5 m deep. Pregnant females formed pairs or small groups. They were not observed to use lairs, but preferentially pupped beside ice ridges or ice-slab piles that afforded shelter to pups. In years when there were few natural leads into the ice-field, females often gave birth on the edge of artificial leads formed by shipping channels. Pups were categorized into stages from newborn (1), white-coat (2), molting (3), and molted (4), with Stage 3 and 4 pups appearing from mid to late February. The nursing period lasted at least 3 weeks and neighboring mother-pup pairs appeared to be mutually tolerant. Mothers left their pups alone or at nursery sites, presumably to forage. Most white-coat pups moved over the ice while avoiding water in response to disturbance from vessels. Mother-pup pairs maintained contact while moving across the ice by a combination of the pup’s following response and diligent chaperoning by the mother. During disturbances some lone pups sought refuge in shelters under ice slabs, whereas others followed a neighboring mother-pup pair away from the vessel. Male-female pairing occurred in late season with no male-male competition observed on the ice. While breeding and pup rearing behavior of Caspian seals has some features in common with that of other Holarctic seals, it is largely distinct and adapted to the unique conditions of the Caspian environment, in particular the paucity of snow cover on the ice
    • …
    corecore