Designs efficiency for non-market valuation with choice modelling: how to measure it, what to report and why

We review the basic principles for the evaluation of design efficiency in discrete choice modelling with a focus on efficiency of WTP estimates from the multinomial logit model. The discussion is developed under the realistic assumption that researchers can plausibly define a prior on the utility coefficients. Some new measures of design performance in applied studies are proposed and their rationale discussed. An empirical example based on the generation and comparison of fifteen separate designs from a common set of assumptions illustrates the relevant considerations to the context of non-market valuation, with particular emphasis placed on C-efficiency. Conclusions are drawn for the practice of reporting in non-market valuation and for future work on design research

Profit Sharing and Investment by Regulated Utilities: a Welfare Analysis

We analyse the effects of different regulatory schemes (price cap and profit sharing) on a firm’s investment of endogenous size. Using a real option approach in continuous time, we show that profit sharing does not delay a firm’s start-up investment relative to a pure price cap scheme. Profit sharing does not necessarily affect total investment either, if the threshold for profit sharing is high enough. Only a profit sharing intervening for low profit levels may delay further investments. We also evaluate the effects of profit sharing on social welfare, determining the level of profit that should optimally trigger tighter regulation: profit sharing should be less stringent in sectors where there are bigger investment opportunities.regulation, investment, profit sharing, real options, RPI-x

Investment Size and Firm’s Value Under Profit Sharing Regulation

In this article we analyse the effects of different regulatory schemes (price cap and profit sharing) on a firm’s investment of endogenous size. Using a real option approach in continuous time, we show that profit sharing does not affect a firm’s start-up decision relative to a pure price cap scheme. Unless the threshold after which profit sharing intervenes is very high, however, introducing a profit sharing element delays further investments: this decreases the present value of total investment. We also evaluate the reduction in the firm’s value due to profit sharing, linking this reduction to the option value of future investments.Regulation, Investment, Profit sharing, Real options, RPI-x

The outskirts of globular clusters as modified gravity probes

In the context of theories of gravity modified to account for the observed dynamics of galactic systems without the need to invoke the existence of dark matter, a prediction often appears regarding low acceleration systems: wherever $a$ falls below $a_{0}$ one should expect a transition from the classical to the modified gravity regime.This modified gravity regime will be characterised by equilibrium velocities which become independent of distance, and which scale with the fourth root of the total baryonic mass, $V^{4} \propto M$. The two above conditions are the well known flat rotation curves and Tully-Fisher relations of the galactic regime. Recently however, a similar phenomenology has been hinted at, at the outskirts of Galactic globular clusters, precisely in the region where $a<a_{0}$. Radial profiles of the projected velocity dispersion have been observed to stop decreasing along Keplerian expectations, and to level off at constant values beyond the radii where $a<a_{0}$. We have constructed gravitational equilibrium dynamical models for a number of globular clusters for which the above gravitational anomaly has been reported, using a modified Newtonian force law which yields equilibrium velocities equivalent to MOND. We find models can be easily constructed having an inner Newtonian region and an outer modified gravity regime, which reproduce all observational constraints, surface brightness profiles, total masses and line of sight velocity dispersion profiles. Through the use of detailed single stellar population models tuned individually to each of the globular clusters in question, we derive estimates of the total masses for these systems. Interestingly, we find that the asymptotic values of the velocity dispersion profiles are consistent with scaling with the fourth root of the total masses, as expected under modified gravity scenarios.Comment: Accepted in ApJ, 13 pages, 7 figure

What is the redshift of the gamma- ray BL Lac source S4 0954+65?

High signal-to-noise ratio spectroscopic observations of the BL Lac object S4 0954+65 at the alleged redshift z = 0.367 are presented. This source was detected at gamma frequencies by MAGIC (TeV) and FERMI (GeV) telescopes during a remarkable outburst that occurred in February 2015, making the determination of its distance particularly relevant for our understanding of the properties of the Extragalactic Background Light. Contrary to previous reports on the redshift, we found that the optical spectrum is featureless at an equivalent width limit of \sim 0.1 Ang. A critical analysis of the existing observations indicates that the redshift is still unknown. Based on the new data we estimate a lower limit to the redshift at z \geq 0.45.Comment: Minor comment and accepted for publication in Astronomical Journa

Evidence for anisotropic motion of the clouds in broad-line regions of BL Lacertae objects

The masses of central massive black holes in BL Lac objects are estimated from their host galaxy absolute magnitude at R-band by using the empirical relation between absolute magnitude of host galaxy and black hole mass. Only a small fraction of BL Lac objects exhibit weak broad-line emission, and we derive the sizes of the broad-line regions (BLRs) in these BL Lac objects from the widths of their broad emission lines on the assumption of the clouds being virilized in BLRs. It is found that the sizes of the BLRs in these sources are usually 2-3 orders of magnitude larger than that expected by the empirical correlation between BLR size and optical luminosity defined by a sample of Seyfert galaxies and quasars. We discuss a variety of possibilities and suggest it may probably be attributed to anisotropic motion of the BLR clouds in these BL Lac objects. If the BLR geometry of these sources is disk-like, the viewing angles between the axis and the line of sight are in the range of 2-12 degrees, which is consistent with the unification schemes.Comment: 5 pages, accepted for publication in Ap

HST Observations of the Optical Jets of PKS 0521-365, 3C371, and PKS 2201+044

HST observations have led to the discovery of the optical counterpart of the radio jet of PKS 2201+044, and to a detailed analysis of the optical jets of PKS 0521-365 and 3C371. At HST spatial resolution these jets are well resolved, displaying knotty morphologies. When compared with radio maps of appropriate resolution, a clear one-to-one correspondence between optical and radio structures is found, showing that all detected optical structures are indeed related to the radio synchrotron emission. Photometry of the brightest knots shows that the radio-to-optical spectral index and the derived intensity of the equipartition magnetic field are approximately constant along the jet. Thus, present observations suggest that the electron energy distribution does not change significantly all along the jet.Comment: Accepted for publications on the Astrphysical Journal. Contains 14 pages and 5 figure

Valuing the Recreational Benefits From the Creation of Nature Reserves in Irish Forests

Data from a large-scale contingent valuation study are used to investigate the effects of forest attributes on willingness to pay for forest recreation in Ireland. In particular, the presence of a nature reserve in the forest is found to significantly increase the visitors' willingness to pay. A random utility model is used to estimate the welfare change associated with the creation of nature reserves in all the Irish forests currently without one. The yearly impact on visitors' economic welfare of new nature reserves approaches half a million pounds per annum, exclusive of non recreational values.Non-market valuation, Contingent valuation, Forest attributes analysis, Nature reserves.