Differences by Degree: Evidence of the Net Financial Rates of Return to Undergraduate Study for England and Wales

This paper provides estimates of the impact of higher education qualifications on the earnings of graduates in the UK by subject studied. We use data from the recent UK Labour Force Surveys which provide a sufficiently large sample to consider the effects of the subject studied, class of first degree, and postgraduate qualifications. Ordinary Least Squares estimates show high average returns for women that does not differ by subject. For men, we find very large returns for Economics, Management and Law but not for other subjects - we even find small negative returns in Arts, Humanities and other Social Sciences. Quantile Regression estimates suggest negative returns for some subjects at the bottom of the distribution, or even at the median. Degree class has large effects in all subjects suggesting the possibility of large returns to effort. Postgraduate study has large effects, independently of first degree class. A large rise in tuition fees across all subjects has only a modest impact on relative rates of return suggesting that little substitution across subjects would occur. The strong message that comes out of this research is that even a large rise in tuition fees makes little difference to the quality of the investment - those subjects that offer high returns (LEM for men, and all subjects for women) continue to do so. And those subjects that do not (especially OSSAH for men) will continue to offer poor returns. The effect of fee rises is dwarfed by existing cross subject differences in returns

Impurity states in multiband s-wave superconductors: analysis of iron pnictides

We examine the effect of a single, non-magnetic impurity in a multiband, extended s-wave superconductor allowing for anisotropy of the gaps on the Fermi surfaces. We derive analytic expressions for the Green's functions in the continuum and analyse the conditions for the existence of sharp impurity-induced resonant states. Underlying band structure is more relevant for the multiband than for single band case, and mismatch between the bands generically makes the formation of the impurity states less likely in the physical regime of parameters. We confirm these conclusions by numerically solving the impurity problem in a tight-binding parameterization of the bands relevant to pnictide superconductors.Comment: minor corrections, published versio

Gravitational Lensing Statistics as a Probe of Dark Energy

By using the comoving distance, we derive an analytic expression for the optical depth of gravitational lensing, which depends on the redshift to the source and the cosmological model characterized by the cosmic mass density parameter $\Omega_m$, the dark energy density parameter $\Omega_x$ and its equation of state $\omega_x = p_x/\rho_x$. It is shown that, the larger the dark energy density is and the more negative its pressure is, the higher the gravitational lensing probability is. This fact can provide an independent constraint for dark energy.Comment: 9 pages, 2 figure