497 research outputs found

    State Participation and the Corporate Value of Natural Resource Economic Rents

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    The asset participation relationship between the state and the corporate entity is an essential determinant of corporate value in the natural resource sector. Natural resources deplete, with the result that oil reserve replacement is an accepted imperative for companies that derive earnings and balance sheet values from global resource assets. Corporate asset values in the sector are underpinned by entitlement to future reserves. Specifically, I show that the global nature of government participation varies and that it matters in which country reserves are held since entitlement structures directly determine how the state and corporate producers share economic rents from resource assets. My global Oil and Gas (O&G) sector study provides market evidence of economic and state variable limits on the value of globalization. Findings revise the low oil price paradigm covered in prior studies and provide evidence that, for O&G producers concerned with reserve replacement, global asset values are directly affected by state entitlement terms. In developed OECD countries, state and corporate agent participation terms are price insensitive, and take the form of concession contracts with royalty or profit taxation terms. By contrast, in emerging NON-OECD countries state agents participate on production sharing terms that are linked to the market price of oil. Relative to comparable OECD oil assets, the value of corporate agent participation in Non-OECD O&G assets is limited by explicit and progressive state agent participation terms that favour sovereign state agent returns.I show that unless price sensitive entitlement clauses are is included in the value of cash flow expectations, state participation terms potentially invert risk return convention under conditions of increasing oil prices. The Fama and French (1993) framework is used to provide market evidence of economic state variable limits on the returns for O&G companies with relatively high asset holdings in Non-OECD countries

    The Impact of Tax Shocks and Oil Price Volatility on Risk - A Study of North Sea Oilfield Projects

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    We examine the impact of market volatility and increased fiscal take on risk in strategic natural resource projects. An increase in 2006 UK oilfield taxation is used as a natural experiment for assessing the impact of a fiscal increase on oilfield projects comprising 73% of UK reserves. Stochastic cash flow at risk models combine market volatility and tax-take at the oilfield level to extend earlier North Sea studies. We demonstrate that a 10% Secondary tax increase in a composite UKCS fiscal system with a-priori nonlinearity directly increases overall cost structures, resulting in a 14% decrease in project values, and significantly, a 67% risk increase for UK Oilfields. Risk effects are asymmetrical across the size varying sample, marginal prospects are most affected. Journal Classification: G12, G31, G32, H2

    Market Risks and Oilfield Ownership - Refining SEC Oil and Gas Disclosures

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    Our paper uses an extensive sample of 292 oilfields to provide evidence that Securities and Exchange Commission (SEC) supplementary disclosures do not capture the price sensitivities of O&G disclosures implicit in the two main forms of oilfield ownership, concession and production sharing contracts (PSCs). SEC present value disclosures for both forms of ownership are shown to be significantly more responsive to oil prices than stock return sensitivities noted by Rajgopal (1999). Importantly, we show that unlike concessions, reserve and production disclosures vary in response to oil price movements for PSC regimes. Our results highlight the need to differentiate PSC disclosures from concession fields, and to fully reflect price risks implicit in oilfield ownership contracts. We extend findings by Rajgopal (1999) and propose refinements necessary to capture contractual price risk effects on SEC disclosures for assets in the O&G sector

    Taxation and Volatility Effects on Real Option Models: A Study of North Sea Oil Fields

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    Real option and dynamic asset valuation techniques are becoming established as standard methods for evaluating investment decisions that are subject to quantifiable uncertainty. This has been particularly the case in natural resources industries. In the UK oil industry there is renewed interest in oilfield valuation techniques - the 22nd UK Offshore Licensing Round was held in 2004 with a total of 97 licences offered to 58 companies in 2004, of which 15 were new entrants to the UK Continental Shelf. Many firms involved in these bid processes now routinely use dynamic modelling and real option valuation to assess oilfield value premiums in differing operating and taxation enviroments. Literature on PV and real option valuation is clear that models should accommodate tax effects but is unclear about its universal treatment in dynamic models. We examine the impact of the North Sea oil industry’s tax regime on the valuation of shelf real options by using a sample of forty oil fields that for the period 1970 to 2001 had initial estimated reserves greater than 75 million barrels of oil. Our sample uses Wood Mackenzie primary source field data updated quarterly by analysts using bottom up field research. Our findings are that the tax enviroment of itself will cause asymmetrical movements in both free cash flow models and option values. These results are of interest to both academics and practitioners in that that tax plays an important role in the valuation process of real options in the oil and gas sector. Our results show that North Sea valuation models that treat taxation as a deterministic function systematically overstate DCF valuation results, understate volatility estimates and undervalue real options. Specifically our analysis suggests that failure to incorporate the variable nature of tax into the valuation process leads to an 18 percent over valuation of asset PV and an under valuation of the option price by 19.5 percent. The increased usage of real option techniques in assessing oil field bids highlights the need for valuation models to incorporate the country specific nature of tax terms. This is especially important for oil fields in the North Sea where field exploration block bidding interest remains high and the legacy of tax changes is long; demanding from financiers a new way of assessing bid values in the face of future cash flow uncertainty. Key words: real option valuation, volatility, taxation JEL classification: G12; G3

    Drosophila melanogaster as a Model Organism of Brain Diseases

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    Drosophila melanogaster has been utilized to model human brain diseases. In most of these invertebrate transgenic models, some aspects of human disease are reproduced. Although investigation of rodent models has been of significant impact, invertebrate models offer a wide variety of experimental tools that can potentially address some of the outstanding questions underlying neurological disease. This review considers what has been gleaned from invertebrate models of neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, metabolic diseases such as Leigh disease, Niemann-Pick disease and ceroid lipofuscinoses, tumor syndromes such as neurofibromatosis and tuberous sclerosis, epilepsy as well as CNS injury. It is to be expected that genetic tools in Drosophila will reveal new pathways and interactions, which hopefully will result in molecular based therapy approaches

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

    Probing the W tb vertex structure in t-channel single-top-quark production and decay in pp collisions at s√=8 TeV with the ATLAS detector

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    To probe the W tb vertex structure, top-quark and W -boson polarisation observables are measured from t-channel single-top-quark events produced in proton-proton collisions at a centre-of-mass energy of 8 TeV. The dataset corresponds to an integrated luminosity of 20.2 fb−1, recorded with the ATLAS detector at the LHC. Selected events contain one isolated electron or muon, large missing transverse momentum and exactly two jets, with one of them identified as likely to contain a b-hadron. Stringent selection requirements are applied to discriminate t-channel single-top-quark events from background. The polarisation observables are extracted from asymmetries in angular distributions measured with respect to spin quantisation axes appropriately chosen for the top quark and the W boson. The asymmetry measurements are performed at parton level by correcting the observed angular distributions for detector effects and hadronisation after subtracting the background contributions. The measured top-quark and W -boson polarisation values are in agreement with the Standard Model predictions. Limits on the imaginary part of the anomalous coupling gR are also set from model-independent measurements.We acknowledge the support of ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; BMWFW and FWF, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq and FAPESP, Brazil; NSERC, NRC and CFI, Canada; CERN; CONICYT, Chile; CAS, MOST and NSFC, China; COLCIENCIAS, Colombia; MSMT CR, MPO CR and VSC CR, Czech Republic; DNRF and DNSRC, Denmark; IN2P3-CNRS, CEA-DSM/IRFU, France; SRNSF, Georgia; BMBF, HGF, and MPG, Germany; GSRT, Greece; RGC, Hong Kong SAR, China; ISF, I-CORE and Benoziyo Center, Israel; INFN, Italy; MEXT and JSPS, Japan; CNRST, Morocco; NWO, Netherlands; RCN, Norway; MNiSW and NCN, Poland; FCT, Portugal; MNE/IFA, Romania; MES of Russia and NRC KI, Russian Federation; JINR; MESTD, Serbia; MSSR, Slovakia; ARRS and MIZS, Slovenia; DST/NRF, South Africa; MINECO, Spain; SRC and Wallenberg Foundation, Sweden; SERI, SNSF and Cantons of Bern and Geneva, Switzerland; MOST, Taiwan; TAEK, Turkey; STFC, United Kingdom; DOE and NSF, United States of America. In addition, individual groups and members have received support from BCKDF, the Canada Council, CANARIE, CRC, Compute Canada, FQRNT, and the Ontario Innovation Trust, Canada; EPLANET, ERC, ERDF, FP7, Horizon 2020 and Marie Sklodowska-Curie Actions, European Union; Investissements d'Avenir Labex and Idex, ANR, Region Auvergne and Fondation Partager le Savoir, France; DFG and AvH Foundation, Germany; Herakleitos, Thales and Aristeia programmes co-financed by EU-ESF and the Greek NSRF; BSF, GIF and Minerva, Israel; BRF, Norway; CERCA Programme Generalitat de Catalunya, Generalitat Valenciana, Spain; the Royal Society and Leverhulme Trust, United Kingdom.The crucial computing support from all WLCG partners is acknowledged gratefully, in particular from CERN, the ATLAS Tier-1 facilities at TRIUMF (Canada), NDGF (Denmark, Norway, Sweden), CC-IN2P3 (France), KIT/GridKA (Germany), INFN-CNAF (Italy), NL-T1 (Netherlands), PIC (Spain), ASGC (Taiwan), RAL (UK) and BNL (USA), the Tier-2 facilities worldwide and large non-WLCG resource providers. Major contributors of computing resoinfo:eu-repo/semantics/publishedVersio

    Search for new particles in events with one lepton and missing transverse momentum in pp collisions at √s = 8 TeV with the ATLAS detector

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    This paper presents a search for new particles in events with one lepton (electron or muon) and missing transverse momentum using 20.3 fb−Âč of proton-proton collision data at √s=8 TeV recorded by the ATLAS experiment at the Large Hadron Collider. No significant excess beyond Standard Model expectations is observed. A Wâ€Č with Sequential Standard Model couplings is excluded at the 95% confidence level for masses up to 3.24 TeV. Excited chiral bosons (W*) with equivalent coupling strengths are excluded for masses up to 3.21 TeV. In the framework of an effective field theory limits are also set on the dark matter-nucleon scattering cross-section as well as the mass scale M* of the unknown mediating interaction for dark matter pair production in association with a leptonically decaying W

    Measurement of W± and Z-boson production cross sections in pp collisions at √s=13 TeV with the ATLAS detector

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    See paper for full list of authors - 17 pages plus author list + cover pages (34 pages total), 5 figures, 3 tables, submitted to Phys. Lett. B, All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2015-03/International audienceMeasurements of the W±→ℓ±ΜW^{\pm} \rightarrow \ell^{\pm} \nu and Z→ℓ+ℓ−Z \rightarrow \ell^+ \ell^- production cross sections (where ℓ±=e±,Ό±\ell^{\pm}=e^{\pm},\mu^{\pm}) in proton-proton collisions at s=13\sqrt{s}=13 TeV are presented using data recorded by the ATLAS experiment at the Large Hadron Collider, corresponding to a total integrated luminosity of 81 pb−1^{-1}. The total inclusive W±W^{\pm}-boson production cross sections times the single-lepton-flavour branching ratios are σW+tot=11.78±0.02(stat)±0.32(sys)±0.59(lumi)\sigma_{W^+}^{tot}= 11.78 \pm 0.02 (stat) \pm 0.32 (sys) \pm 0.59 (lumi) nb and σW−tot=8.75±0.02(stat)±0.24(sys)±0.44(lumi)\sigma_{W^-}^{tot} = 8.75 \pm 0.02 (stat) \pm 0.24 (sys) \pm 0.44 (lumi) nb for W+W^+ and W−W^-, respectively. The total inclusive ZZ-boson production cross section times leptonic branching ratio, within the invariant mass window 66<mℓℓ<11666 < m_{\ell\ell} < 116 GeV, is σZtot=1.97±0.01(stat)±0.04(sys)±0.10(lumi)\sigma_{Z}^{tot} = 1.97 \pm 0.01 (stat) \pm 0.04 (sys) \pm 0.10 (lumi) nb. The W+W^+, W−W^-, and ZZ-boson production cross sections and cross-section ratios within a fiducial region defined by the detector acceptance are also measured. The cross-section ratios benefit from significant cancellation of experimental uncertainties, resulting in σW+fid/σW−fid=1.295±0.003(stat)±0.010(sys)\sigma_{W^+}^{fid}/\sigma_{W^-}^{fid} = 1.295 \pm 0.003 (stat) \pm 0.010 (sys) and σW±fid/σZfid=10.31±0.04(stat)±0.20(sys)\sigma_{W^{\pm}}^{fid}/\sigma_{Z}^{fid} = 10.31 \pm 0.04 (stat) \pm 0.20 (sys). Theoretical predictions, based on calculations accurate to next-to-next-to-leading order for quantum chromodynamics and next-to-leading order for electroweak processes and which employ different parton distribution function sets, are compared to these measurements

    Search for charged Higgs bosons through the violation of lepton universality in tÂŻt events using pp collision data at ps = 7 TeV with the ATLAS experiment

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    In several extensions of the Standard Model, the top quark can decay into a bottom quark and a light charged Higgs boson H+, t → bH+, in addition to the Standard Model decay t → bW. Since W bosons decay to the three lepton generations equally, while H+ may predominantly decay into Ï„Îœ, charged Higgs bosons can be searched for using the violation of lepton universality in top quark decays. The analysis in this paper is based on 4.6 fb−1 of proton-proton collision data at √s = 7 TeV collected by the ATLAS experiment at the Large Hadron Collider. Signatures containing leptons (e or ÎŒ) and/or a hadronically decaying τ (τhad) are used. Event yield ratios between e+τhad and e+ÎŒ, as well as between ÎŒ+τhad and ÎŒ+e, final states are measured in the data and compared to predictions from simulations. This ratio-based method reduces the impact of systematic uncertainties in the analysis. No significant deviation from the Standard Model predictions is observed. With the assumption that the branching fraction B(H+ → Ï„Îœ) is 100%, upper limits in the range 3.2%–4.4% can be placed on the branching fraction B(t → bH+) for charged Higgs boson masses mH+ in the range 90–140GeV. After combination with results from a search for charged Higgs bosons in tÂŻt decays using the τhad+jets final state, upper limits on B(t → bH+) can be set in the range 0.8%–3.4%, for mH+ in the range 90–160GeV
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