Precaution: principles and practice in Australian environmental and natural resource management

Precaution: principles and practice in Australian environmental and natural resource management by Deborah Peterson, was presented as the Presidential Address to the 50th Annual Australian Agricultural and Resource Economics Society Conference, Manly, New South Wales, 8 - 10 February 2006. Since the late 1980s, the concept of precaution has been incorporated into numerous international agreements and laws, as well as in domestic statutes and policies in many countries. This paper examines the international emergence of the concept and its application in Australia. Despite rapid growth in adoption of the so-called "precautionary principle," the concept remains highly controversial, and its success in terms of improving environmental and natural resource management has been questioned. This paper argues that implementation guidelines are essential to ensure that precautionary decision making is consistent with good decision making principles, and to avoid unnecessary costs and the potential for perverse outcomes. Economists have an important role in contributing to these guidelines and in developing techniques for incorporating uncertainty into decision making. The views expressed in this paper do not necessarily reflect those of the Australian Government or the Productivity Commission.Resource /Energy Economics and Policy,

Precaution: principles and practice in Australian environmental and natural resource management

Since the late 1980s, the concept of precaution has been incorporated into numerous international agreements and laws, as well as in domestic statutes and policies in many countries. This paper examines the international emergence of the concept and its application in Australia. Despite rapid growth in adoption of the so-called ‘precautionary principle’, the concept remains highly controversial, and its success in terms of improving environmental and natural resource management has been questioned. A common misconception is that the principle prescribes action. In fact, internationally accepted definitions are about decision-making processes. This paper argues that implementation guidelines are essential to ensure that precautionary decision-making is consistent with good decision-making principles, and to avoid unnecessary costs and perverse outcomes.environment, natural resource management, precautionary principle, uncertainty, Environmental Economics and Policy, Resource /Energy Economics and Policy,

Special issue on water economics and policy

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Third-party effects of water trading and potential policy responses

A key feature of water policy reform in Australia has been the separation of water access entitlements from land titles and the establishment of markets for water. However, the separation of water entitlements from land failed to account for a number of characteristics that were implicit in the joint right. This has given rise to a number of third-party effects as water is traded in an incomplete market. This paper describes four third-party effects of water trade; reliability of supply, timeliness of delivery, storage and delivery charges, and water quality and examines policy responses to address these effects. The discussion draws on the concepts of exclusiveness and rivalry to determine the applicability of property rights and other solutions to the third-party effects of trade. It is likely that many of the third-party effects of trade discussed in this paper do not warrant policy intervention at the national or state level, but intervention at the local level may be warranted. The costs of addressing some third-party effects may outweigh the benefits. Where there are significant gains from trade, the existence of these third-party effects should not been seen as a reason to impede trade.property rights, water trading, third-party effects, Resource /Energy Economics and Policy,

Irrigation externalities: pricing and charges

Irrigation externalities: pricing and charges by Gavan Dwyer, Robert Douglas, Deb Peterson, Jo Chong and Kate Maddern was released on 14 March 2006. The paper discusses the nature and causes of environmental change related to rural water use, and provides a taxonomy of the many diverse types. It also examines the issues surrounding possible charges on water use for water related externalities. There have been few attempts by water utilities to incorporate externalities into full cost pricing of irrigation water. The aim of this Staff Working Paper was to: examine the extent to which charges imposed by irrigation water utilities could address externalities from irrigation water supply and use; and to develop a framework to identify and characterise changes in environmental conditions from the supply and use of irrigation water that may lead to environmental externalities. The authors found that many factors influence the extent to which charging for water would change water use. These include the volume of water available to irrigators, the extent to which trade can occur, the size of the charge or tax, the price responsiveness for irrigation water and the existing mechanisms to address externalities. A tax on water use may increase economic efficiency where external costs are related only to the level of water use. However, such a tax is an unsuitable instrument if the Government's policy objective is to reduce environmental damage to a predetermined level or to raise a target level of revenue to address the externalities. The views expressed in this paper are those of the staff involved and do not necessarily reflect those of the Productivity Commission.Resource /Energy Economics and Policy,

Direct determination of optimal real-space orbitals for correlated electronic structure of molecules

We demonstrate how to determine nearly numerically exact orthonormal orbitals that are optimal for evaluation of the energy of arbitrary (correlated) states of atoms and molecules by minimization of the energy Lagrangian. Orbitals are expressed in real space using multiresolution spectral element basis that is refined adaptively to achieve the user-specified target precision while avoiding the ill-conditioning issues that plague AO basis set expansions traditionally used for correlated models of molecular electronic structure. For light atoms the orbital solver in conjunction with a variational electronic structure model [selected Configuration Interaction (CI)] provides energies of comparable precision to a state-of-the-art atomic CI solver. The computed electronic energies of atoms and molecules are significantly more accurate than the counterparts obtained with the Gaussian AO bases of the same rank, and can be determined even when linear dependence issues preclude the use of the AO bases.Comment: 25 pages, 2 figure

BLR Physical Conditions in Extreme Population A Quasars: a Method to Estimate Central Black Hole Mass at High Redshift

We describe a method for determination of physical conditions in the broad line regions of a significant subsample of Seyfert-1 nuclei and quasars. Several diagnostic ratios based on intermediate (AlIII 1860, SiIII 1892) and high (CIV 1549, SiIV 1397) ionization lines in the UV spectra of quasars are used to constrain density, ionization and metallicity of the emitting gas. We apply the method to two extreme Population A quasars - the prototypical NLSy1 I Zw 1 and a high-z\ NLSy1-like object, SDSS J120144.36+011611.6. We find well-defined physical conditions: low ionization (ionization parameter $< 10^{-2}$), high density (10$^{12} - 10^{13}$ cm^{-3}) and significant metal enrichment. Ionization parameter and density can be derived independently for each source with an uncertainty that is always less than $\pm 0.3$ in logarithm. We use the product density times ionization parameter to estimate the broad line region radius and the virial black hole mass. Estimates of black hole masses based on the "photoionization" analysis described in this paper are probably more accurate than those derived from the radius - luminosity correlation.Comment: Accepted for publication in The Astrophysical Journa

The Prevalence of Cognitive Impairment Among Adults With Incident Heart Failure: The “Reasons for Geographic and Racial Differences in Stroke” (REGARDS) Study

Background Cognitive impairment (CI) is estimated to be present in 25%–80% of heart failure (HF) patients, but its prevalence at diagnosis is unclear. To improve our understanding of cognition in HF, we determined the prevalence of CI among adults with incident HF in the REGARDS study. Methods and Results REGARDS is a longitudinal cohort study of adults ≥45 years of age recruited in the years 2003–2007. Incident HF was expert adjudicated. Cognitive function was assessed with the Six-Item Screener. The prevalence of CI among those with incident HF was compared with the prevalence of CI among an age-, sex-, and race-matched cohort without HF. The 436 participants with incident HF had a mean age of 70.3 years (SD 8.9), 47% were female, and 39% were black. Old age, black race, female sex, less education, and anticoagulation use were associated with CI. The prevalence of CI among participants with incident HF (14.9% [95% CI 11.7%–18.6%]) was similar to the non-HF matched cohort (13.4% [11.6%–15.4%]; P < .43). Conclusions A total of 14.9% of the adults with incident HF had CI, suggesting that the majority of cognitive decline occurs after HF diagnosis. Increased awareness of CI among newly diagnosed patients and ways to mitigate it in the context of HF management are warranted

Limits on the ultra-bright Fast Radio Burst population from the CHIME Pathfinder

We present results from a new incoherent-beam Fast Radio Burst (FRB) search on the Canadian Hydrogen Intensity Mapping Experiment (CHIME) Pathfinder. Its large instantaneous field of view (FoV) and relative thermal insensitivity allow us to probe the ultra-bright tail of the FRB distribution, and to test a recent claim that this distribution's slope, $\alpha\equiv-\frac{\partial \log N}{\partial \log S}$, is quite small. A 256-input incoherent beamformer was deployed on the CHIME Pathfinder for this purpose. If the FRB distribution were described by a single power-law with $\alpha=0.7$, we would expect an FRB detection every few days, making this the fastest survey on sky at present. We collected 1268 hours of data, amounting to one of the largest exposures of any FRB survey, with over 2.4\,$\times$\,10$^5$\,deg$^2$\,hrs. Having seen no bursts, we have constrained the rate of extremely bright events to $<\!13$\,sky$^{-1}$\,day$^{-1}$ above $\sim$\,220$\sqrt{(\tau/\rm ms)}$ Jy\,ms for $\tau$ between 1.3 and 100\,ms, at 400--800\,MHz. The non-detection also allows us to rule out $\alpha\lesssim0.9$ with 95$\%$ confidence, after marginalizing over uncertainties in the GBT rate at 700--900\,MHz, though we show that for a cosmological population and a large dynamic range in flux density, $\alpha$ is brightness-dependent. Since FRBs now extend to large enough distances that non-Euclidean effects are significant, there is still expected to be a dearth of faint events and relative excess of bright events. Nevertheless we have constrained the allowed number of ultra-intense FRBs. While this does not have significant implications for deeper, large-FoV surveys like full CHIME and APERTIF, it does have important consequences for other wide-field, small dish experiments