1,339 research outputs found

    Supplier-Induced Demand and Quality Competition: An Empirical Investigation

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    The observable difference between "demand inducement" and "promotion" or "sales" is subjective and difficult to measure. Demand inducement has a pejorative connotation and is usually associated with significant asymmetric information. The evidence supporting the supplier-induced demand hypothesis in medicine is consistent with an alternate, more competitive hypothesis. Increasing competition may lead to higher service quality. If so, one could find a positive correlation between fees for service and the number of physicians in the community. This paper contains an empirical model that helps discriminate between these two competing hypotheses. We also provide empirical evidence on the role of income effects in the supplier induced demand debate suggested recently by McGuire and Pauly [1991].Medicine; Physician; Physicians

    Looking ahead: subjective time perception and individual discounting

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    Time discounting is at the heart of economic decision-making. We disentangle hyperbolic discounting from subjective time perception using experimental data from incentive-compatible tests to measure time preferences, and a set of experimental tasks to measure time perception. The two behavioural parameters may be related to two factors that affect how we look ahead to future events. The first is that some component of time preferences reflect hyperbolic discounting. The second factor is that non-constant discounting may also be a reflection of subjective time perception: if people’s perception of time follows a near logarithmic process (as all other physiological perceptions such as heat, sound, and light do) then all existing estimates of individual discounting will be mis-measured and incorrectly suggest “hyperbolic” discounting, even if discounting over subjective time is constant. To test these hypotheses, we empirically estimate the two distinct behavioural parameters using data collected from 178 participants to an experiment conducted at the London School of Economics Behavioural Research Lab. The results support the hypothesis that apparent non-constant discounting is largely a reflection of subjective time perception

    System using leo satellites for centimeter-level navigation

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    Disclosed herein is a system for rapidly resolving position with centimeter-level accuracy for a mobile or stationary receiver [4]. This is achieved by estimating a set of parameters that are related to the integer cycle ambiguities which arise in tracking the carrier phase of satellite downlinks [5,6]. In the preferred embodiment, the technique involves a navigation receiver [4] simultaneously tracking transmissions [6] from Low Earth Orbit Satellites (LEOS) [2] together with transmissions [5] from GPS navigation satellites [1]. The rapid change in the line-of-sight vectors from the receiver [4] to the LEO signal sources [2], due to the orbital motion of the LEOS, enables the resolution with integrity of the integer cycle ambiguities of the GPS signals [5] as well as parameters related to the integer cycle ambiguity on the LEOS signals [6]. These parameters, once identified, enable real-time centimeter-level positioning of the receiver [4]. In order to achieve high-precision position estimates without the use of specialized electronics such as atomic clocks, the technique accounts for instabilities in the crystal oscillators driving the satellite transmitters, as well as those in the reference [3] and user [4] receivers. In addition, the algorithm accommodates as well as to LEOS that receive signals from ground-based transmitters, then re-transmit frequency-converted signals to the ground

    The Effect of Direct to Consumer Television Advertising on the Timing of Treatment

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    We examine how direct to consumer advertising (DCA) affects the delay between diagnosis and pharmacological treatment for patients suffering from a common chronic disease. The primary data for this study consist of patients diagnosed with osteoarthritis (N=18,235) taken from a geographically diverse national research network of 72 primary care practices with 348 physicians in 27 states over the 1999 to 2002 time period. Brand specific advertising data was collected for local and network television at the monthly-level for the nearest media markets to the practices. Results of duration models of delay to treatment suggest advertising does affect the length of time that patients and physicians wait to initiate therapy. This evidence suggests these effects may be welfare enhancing, in that advertising tends to encourage more rapid adoption among patients who are good clinical candidates for the therapy, and leads to less rapid adoption among some patients who are poor clinical candidates.Health and Safety, Technology and Industry

    Improving Human Health by Increasing Access to Natural Areas: Linking Research to Action at Scale

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    Report of the 2014 Berkley Workshop Held at the Wingspread Conference Center, Johnson Foundation, Racine, Wisconsin - June 201

    NICMOS Imaging of the HR 4796A Circumstellar Disk

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    We report the first near infrared (NIR) imaging of a circumstellar annular disk around the young (~8 Myr), Vega-like star, HR 4796A. NICMOS coronagraph observations at 1.1 and 1.6 microns reveal a ring-like symmetrical structure peaking in reflected intensity 1.05 arcsec +/- 0.02 arcsec (~ 70 AU) from the central A0V star. The ring geometry, with an inclination of 73.1 deg +/- 1.2 deg and a major axis PA of 26.8 deg +/- 0.6 deg, is in good agreement with recent 12.5 and 20.8 micron observations of a truncated disk (Koerner, et al. 1998). The ring is resolved with a characteristic width of less than 0.26 arcsec (17 AU) and appears abruptly truncated at both the inner and outer edges. The region of the disk-plane inward of ~60 AU appears to be relatively free of scattering material. The integrated flux density of the part of the disk that is visible (greater than 0.65 arcsec from the star) is found to be 7.5 +/- 0.5 mJy and 7.4 +/- 1.2 mJy at 1.1 and 1.6 microns, respectively. Correcting for the unseen area of the ring yields total flux densities of 12.8 +/- 1.0 mJy and 12.5 +/- 2.0 mJy, respectively (Vega magnitudes = 12.92 /+- 0.08 and 12.35 +/-0.18). The NIR luminosity ratio is evaluated from these results and ground-based photometry of the star. At these wavelengths Ldisk(lambda)/L*(lambda) = 1.4 +/- 0.2E-3 and 2.4 +/- 0.5E-3, giving reasonable agreement between the stellar flux scattered in the NIR and that which is absorbed in the visible and re-radiated in the thermal infrared. The somewhat red reflectance of the disk at these wavelengths implies mean particle sizes in excess of several microns, larger than typical interstellar grains. The confinement of material to a relatively narrow annular zone implies dynamical constraints on the disk particles by one or more as yet unseen bodies.Comment: 14 pages, 1 figure for associated gif file see: http://nicmosis.as.arizona.edu:8000/AAS99/FIGURE1_HR4796A_ApJL.gif . Accepted 13 January 1999, Astrophyical Journal Letter

    Registration of hard white winter wheat germplasms KS14U6380R5, KS16U6380R10, and KS16U6380R11 with adult plant resistance to stem rust

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    Resistance to the Ug99 group of races of the stem rust fungus Puccinia graminis f. sp. tritici is limited in winter wheat (Triticum aestivum L.) germplasm adapted to the Great Plains of the United States. Our objective was to generate regionally adapted hard winter wheat germplasm with combinations of adult plant resistance genes that are expected to provide durable resistance. KS14U6380R5 (Reg. no. GP-1043, PI 689115), KS16U6380R10 (Reg. no. GP-1044, PI 689116), and KS16U6380R11 (Reg. no. GP-1045, PI 689117) were derived from backcrosses of the hard white winter wheat germplasm KS05HW14 to the stem rust-resistant Kenyan spring wheat cultivar ‘Kingbird’. KS14U6380R5, KS16U6380R11, and KS16U6380R10 were developed by pedigree selection and were initially evaluated as U6380-11-2R-0A, U6380-210-2R-0A, and U6380-148-4R-2T, respectively. The germplasms were developed by the USDA-ARS and jointly released with the Kansas State University Agricultural Experiment Station. These germplasms provide parents for development of hard winter wheat cultivars with durable resistance to stem rust

    Looking ahead: subjective time perception and individual discounting

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    We disentangle hyperbolic discounting from subjective time perception using experimental data from incentive-compatible tests to measure time preferences, and a set of experimental tasks to measure time perception. Two behavioral parameters are related to two factors affecting how we look ahead to future events. The first is some component of time preferences reflecting hyperbolic discounting. The second factor is that non-constant discounting may also be a reflection of subjective time perception: if people’s perception of time follows a near logarithmic process (as heat, sound, and light do) then estimates of individual discounting will be mis-measured and incorrectly suggest hyperbolic discounting even if discounting over subjective time is constant. We empirically estimate the two distinct behavioral parameters using data collected from 178 participants in a lab experiment. The results support the hypothesis that apparent non-constant discounting is largely a reflection of non-linear subjective time perception
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