123 research outputs found
Liquid assets, liquidity constraints and global imbalances.
The world distribution of current account balances has been steadily drifting away from ânormalityâ since 1997. This puzzling development has occurred in parallel with large scale accumulation of official foreign reserve assets in emerging Asia and commodity exporting countries, and a growing role of portfolio flows in financing the US external deficit. The theoretical toolbox that was used to understand âold puzzlesâ of international macroeconomics may still be relevant to address these new puzzles, to the extent that it focuses more specifically on liquidity aspects: uneven supply of liquid assets, borrowing constraints, and externalities related to financial infrastructures that foster market liquidity. The paper discusses how these various features have been introduced in the most recent literature on global imbalances. One aspect that may require further examination is the role of fi nancial market liquidity as a âpublic good externalityâ: in the absence of appropriate provision of such a public good in emerging economies, reserve accumulation may be seen as an attempt to import the âpublic servicesâ benefi ts of holding liquid ârisk-freeâ assets. This may in turn possibly result in a form of âcongestionâ if US dollar reserve accumulation outpaces the issuance of US Treasuries or equivalent securities. Large reserve holders have thus turned to a wider range of asset classes, including asset-backed securities whose liquidity has all but vanished in the course of recent fi nancial market turbulences. These developments could therefore affect the fi nancing conditions of the US current account deficit, and undermine some of its structural determinants.
Lâaccumulation de rĂ©serves de change est-elle un indicateur dâenrichissement dâune nation ?
Les rĂ©serves de change accumulĂ©es par certaines Ă©conomies dâAsie Ă©mergente dĂ©passent les montants justifiĂ©s par des motifs dâassurance. Reflet de stratĂ©gies de change mercantilistes, elles peuvent ĂȘtre le symptĂŽme dâune croissance dĂ©sĂ©quilibrĂ©e.rĂ©serves de change, termes de lâĂ©change, croissance Ă©conomique.
Liquidity, Moral Hazard and Inter-Bank Market Collapse.
This paper proposes a framework to analyze the functioning of the inter-bank liquidity market and the occurrence of liquidity crises. The model relies on three key assumptions: (i) liquidity provisioning is not verifiable -it cannot be contracted upon-, (ii) banks face moral hazard when confronted with liquidity shocks-unobservable effort can help overcome the shock-, (iii) liquidity shocks are private information - they cannot be diversified away-. Under these assumptions, the equilibrium risk-adjusted return on liquidity provisioning increases with the aggregate equilibrium volume of ex ante liquidity provision. As a consequence, banks may provision too little liquidity compared with the social optimum. Within this framework we derive two main results. First inter-bank market collapse is an equilibrium. Second such an equilibrium is more likely when (i) the individual probability of the liquidity shock is lower, (ii) ex ante competition between banks on illiquid long term assets is larger.Liquidity Crisis ; Moral Hazard ; Interbank Market ; Competition
Soil methane and carbon dioxide fluxes from cropland and riparian buffers in different hydrogeomorphic settings
Riparian buffers contribute to the mitigation of nutrient pollution in agricultural landscapes, but there is concern regarding their potential to be hot spots of greenhouse gas production. This study compared soil CO2 and CH4 fluxes in adjacent crop fields and riparian buffers (a flood-prone forest and a flood-protected grassland along an incised channel) and examined the impact of water table depth (WTD) and flood events on the variability of gas fluxes in riparian zones. Results showed significantly (P 22°C), but the effect of flooding was less pronounced in early spring (emission <1.06 mg CH4âC mâ2 dâ1), probably due to low soil temperature. Although CH4 flux direction alternated at all sites, overall the croplands and the flood-affected riparian forest were CH4 sources, with annual emission averaging +0.04 ± 0.17 and +0.92 ± 1.6 kg CH4âC haâ1, respectively. In the riparian forest, a topographic depression (<8% of the total area) accounted for 78% of the annual CH4 emission, underscoring the significance of landscape heterogeneity on CH4 dynamics in riparian buffers. The nonflooded riparian grassland, however, was a net CH4 sink (â1.08 ± 0.22 kg CH4âC haâ1 yrâ1), probably due to the presence of subsurface tile drains and a dredged/incised channel at that study site. Although these hydrological alterations may have contributed to improvement in the CH4 sink strength of the riparian grassland, this must be weighed against the water quality maintenance functions and other ecological services provided by riparian buffers
Contesting authentic practice and ethical authority in adventure tourism
This paper examines the discourses of authenticity and ethics used among adventure tourists regarding the use of the natural environment. In one case, full-time traveling rock climbers use their dedication to the sport and annual visits to the Red River Gorge as evidence for their authoritative voice on ethical climbing practice. While they identify the growing numbers of leisure climbers as a problem for sustainability, many also take up temporary employment as guides and are directly involved in the introduction of new climbers to the area. In another case, two groups of wilderness enthusiasts â âADK 46ersâ and âSummit Stewardsâ â lament the environmental and social impacts of other recreational users in the Adirondack Park. Despite being visitors themselves, Summit Stewards and 46ers use their sense of place and knowledge of Adirondack history and ecology to substantiate their authority as purveyors of ethical practice. In both cases, senses of responsibility are inspired by senses of place, but are articulated through notions of authenticity and used as justification for ethical authority. While validating their presence in these outdoor spaces, the use of such rhetoric also minimizes their own impacts yielding further tensions among user groups
Transverse-momentum-dependent Multiplicities of Charged Hadrons in Muon-Deuteron Deep Inelastic Scattering
A semi-inclusive measurement of charged hadron multiplicities in deep
inelastic muon scattering off an isoscalar target was performed using data
collected by the COMPASS Collaboration at CERN. The following kinematic domain
is covered by the data: photon virtuality (GeV/), invariant
mass of the hadronic system GeV/, Bjorken scaling variable in the
range , fraction of the virtual photon energy carried by the
hadron in the range , square of the hadron transverse momentum
with respect to the virtual photon direction in the range 0.02 (GeV/ (GeV/). The multiplicities are presented as a
function of in three-dimensional bins of , , and
compared to previous semi-inclusive measurements. We explore the
small- region, i.e. (GeV/), where
hadron transverse momenta are expected to arise from non-perturbative effects,
and also the domain of larger , where contributions from
higher-order perturbative QCD are expected to dominate. The multiplicities are
fitted using a single-exponential function at small to study
the dependence of the average transverse momentum on , and . The power-law behaviour of the
multiplicities at large is investigated using various
functional forms. The fits describe the data reasonably well over the full
measured range.Comment: 28 pages, 20 figure
Light isovector resonances in Ï-p âÏ-Ï-Ï+p at 190 GeV/c
We have performed the most comprehensive resonance-model fit of Ï-Ï-Ï+ states using the results of our previously published partial-wave analysis (PWA) of a large data set of diffractive-dissociation events from the reaction Ï-+pâÏ-Ï-Ï++precoil with a 190 GeV/c pion beam. The PWA results, which were obtained in 100 bins of three-pion mass, 0.5<2.5 GeV/c2, and simultaneously in 11 bins of the reduced four-momentum transfer squared, 0.1<1.0 (GeV/c)2, are subjected to a resonance-model fit using Breit-Wigner amplitudes to simultaneously describe a subset of 14 selected waves using 11 isovector light-meson states with JPC=0-+, 1++, 2++, 2-+, 4++, and spin-exotic 1-+ quantum numbers. The model contains the well-known resonances Ï(1800), a1(1260), a2(1320), Ï2(1670), Ï2(1880), and a4(2040). In addition, it includes the disputed Ï1(1600), the excited states a1(1640), a2(1700), and Ï2(2005), as well as the resonancelike a1(1420). We measure the resonance parameters mass and width of these objects by combining the information from the PWA results obtained in the 11 tâČ bins. We extract the relative branching fractions of the Ï(770)Ï and f2(1270)Ï decays of a2(1320) and a4(2040), where the former one is measured for the first time. In a novel approach, we extract the tâČ dependence of the intensity of the resonances and of their phases. The tâČ dependence of the intensities of most resonances differs distinctly from the tâČ dependence of the nonresonant components. For the first time, we determine the tâČ dependence of the phases of the production amplitudes and confirm that the production mechanism of the Pomeron exchange is common to all resonances. We have performed extensive systematic studies on the model dependence and correlations of the measured physical parameters
Measurement of P T -weighted Sivers asymmetries in leptoproduction of hadrons
The transverse spin asymmetries measured in semi-inclusive leptoproduction of hadrons, when weighted
with the hadron transverse momentum PT , allow for the extraction of important transverse-momentumdependent distribution functions. In particular, the weighted Sivers asymmetries provide direct information
on the Sivers function, which is a leading-twist distribution that arises from a correlation between the transverse momentum of an unpolarised quark in a transversely polarised nucleon and the spin of the nucleon.
Using the high-statistics data collected by the COMPASS Collaboration in 2010 with a transversely polarised proton target, we have evaluated two types of PT -weighted Sivers asymmetries, which are both
proportional to the product of the first transverse moment of the Sivers function and of the fragmentation
function. The results are compared to the standard unweighted Sivers asymmetries and used to extract the
first transverse moments of the Sivers distributions for u and d quark
Triangle Singularity as the Origin of the a1(1420)
The COMPASS Collaboration experiment recently discovered a new isovector resonancelike signal with axial-vector quantum numbers, the a(1)(1420), decaying to f(0)(980)(pi). With a mass too close to and a width smaller than the axial-vector ground state a(1)(1260), it was immediately interpreted as a new light exotic meson, similar to the X, Y, Z states in the hidden-charm sector. We show that a resonancelike signal fully matching the experimental data is produced by the decay of the a(1) (1260) resonance into K* (-> K pi) (K) over bar and subsequent rescattering through a triangle singularity into the coupled f(0)(980)p channel. The amplitude for this process is calculated using a new approach based on dispersion relations. The triangle-singularity model is fitted to the partial-wave data of the COMPASS experiment. Despite having fewer parameters, this fit shows a slightly better quality than the one using a resonance hypothesis and thus eliminates the need for an additional resonance in order to describe the data. We thereby demonstrate for the first time in the lightmeson sector that a resonancelike structure in the experimental data can be described by rescattering through a triangle singularity, providing evidence for a genuine three-body effect
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