The Optimal Number of Charities

In this paper charity brings some joy of giving; it yields more contributions to public goods than standard "subscription", but its creation is costly. We compare the laissez-faire number of charities with both the second and the first-best level. In general, laissez-faire implies an underprovision of both charities and public goods.Charities, Public Good

The Optimal Number of Charities

In this paper charity brings some joy of giving; it yields more contributions to public goods than standard "subscription", but its creation is costly. We compare the laissez-faire number of charities with both the second and the first-best level. In general, laissez-faire implies an underprovision of both charities and public goods.Charities, Public Good

Explaining Africa’s public consumption procyclicality : revisiting old evidence

This paper compiles a novel dataset of time-varying measures of government consumption cyclicality for a panel of 46 African economies between 1960 and 2014. Government consumption has, generally, been highly procyclical over time in this group of countries. However, sample averages hide serious heterogeneity across countries with the majority of them showing procyclical behavior despite some positive signs of graduation from the “procyclicality trap” in a few cases. By means of weighted least squares regressions, we find that more developed African economies tend to have a smaller degree of government consumption procyclicality. Countries with higher social fragmentation and those are more reliant on foreign aid inflows tend to have a more procyclical government consumption policy. Better governance promotes counter- cyclical fiscal policy whileincreased democracy dampens it. Finally, some fiscal rules are important in curbing the procyclical behavior of government consumption.info:eu-repo/semantics/publishedVersio

Ropivacaine decreases tissue oxygen saturation following peripheral nerve block in children

Background: Local anesthetics can cause vasoconstriction and disrupt neuronal impulses, reducing regional blood flow and increasing tissue oxygen consumption. This could alter regional oxygen supply and demand. Because microcirculation modifies during development and oxygen consumption kinetics differ between children and adults, we aimed to assess effects of ropivacaine Peripheral Nerve Block (PNB) on regional tissue saturation in children and young adults using Near-Infrared Spectroscopy (NIRS). Methods: Following Institutional Review Board approval and informed consent, 20 patients undergoing PNB for various orthopedic surgeries were studied. NIRS sensors were placed on the operative limb, contralateral limb, and forehead. Tissue saturations (rSO2) were recorded at baseline and every 5 minutes for 60 minutes following ropivacaine PNB. Mean rSO2 was assessed with repeated measures ANOVA. Correlation of tissue rSO2 with cerebral oximetry was calculated and significance determined with student’s t-test. Results: In all patients, blocked limb rSO2 decreased significantly compared to control limb 20 minutes after injection and remained lower. Control limb rSO2 and cerebral oximetry did not change over time. Non-blocked limb rSO2 demonstrated weak but significant correlation with cerebral oximetry while blocked limb rSO2 showed no correlation. Mean change in blocked limb rSO2 from baseline was significantly negative compared to a net positive mean change in the non-blocked limb. Conclusions: Decreased rSO2 following PNB suggests reduced local blood flow due to vasoconstriction, increased tissue oxygen consumption, or both. Changes in rSO2 provide an opportunity to develop NIRS as a non-invasive tool to identify successful PNB. Local anesthetic-induced decline in rSO2 could have implications in operative settings with ischemia or low-flow

About estimations of an one-photon background in neutrino oscillation experiments at low neutrino energies

The possible sources of one-photon radiation as background for quasi-elastic reaction nu_mu+n to mu^-+p are considered. The ones are relevant in experiments on determination of oscillation parameters at low neutrino energies (E_nu^lab~1 GeV). The estimation for the cross section of reaction nu_mu+n to mu^-+p+gamma is given at E_nu^lab=0.7 GeV as 0.65% from the corresponding cross section of quasi-elastic reaction.Comment: 17 pages, 10 figure

Ioffe-time distributions instead of parton momentum distributions in description of deep inelastic scattering

We argue that parton distributions in coordinate space provide a more natural object for nonperturbative methods compared to the usual momentum distributions in which the physics of different longitudinal distances is being mixed. To illustrate the advantages of the coordinate space formulation, we calculate the coordinate space distributions for valence quarks in the proton using the QCD sum rule approach. A remarkable agreement is found between the calculated and the experimentally measured u-quark distribution up to light-cone distances $\Delta^- = \Delta^0 - \Delta^3$ of order $\sim 1$ fm in the proton rest frame. The calculation for valence d quarks gives much worse results; the reasons for this discrepancy are discussed.Comment: 24 pages plus 13 pages with figures, requires epsf.sty, revised version to appear in Phys.Rev.

Gauge invariance and finite width effects in radiative two-pion tau lepton decay

The contribution of the rho^{\pm} vector meson to the tau -> pi pi nu gamma decay is considered as a potential source for the determination of the magnetic dipole moment of this light vector meson. In order to keep gauge-invariance of the whole decay amplitude, a procedure similar to the fermion loop-scheme for charged gauge bosons is implemented to incorporate the finite width effects of the rho^{\pm} vector meson. The absorptive pieces of the one-loop corrections to the propagators and electromagnetic vertices of the rho^{\pm} meson and W^{\pm} gauge boson have identical forms in the limit of massless particles in the loops, suggesting this to be a universal feature of spin-one unstable particles. Model-dependent contributions to the tau -> pi pi nu gamma decay are suppressed by fixing the two-pion invariant mass distribution at the rho meson mass value. The resulting photon energy and angular distribution is relatively sensitive to the effects of the rho magnetic dipole moment.Comment: 22 pages, 4 postscript figures, references and comments on relevance of perturbative treatment of rho electromagnetic vertex are added, accepted for pub. in Phys. Rev.

Socially optimal contribution rate and cap in a proportional (DC) pension system

In our model, the government operates a mandatory proportional (DC) pension system to substitute for the low life-cycle savings of the lower-paid myopic workers, while maintaining the incentives of the higher-paid far-sighted ones in contributing to the system. The introduction of an appropriate cap on pension contribution (or its base)—excluding the earnings above the cap from the contribution base—raises the optimal contribution rate, helping more the lower-paid myopic workers and reserving enough room for the saving of higher-paid far-sighted ones. The social welfare is almost independent of the cap in a relatively wide interval but the maximal welfare is higher than the capless welfare by 0.3–4.5 %.info:eu-repo/semantics/publishedVersio