Online Appendix to "Training, search and wage dispersion"

Online appendix for the Review of Economic Dynamics article

Equilibrium Tuition, Applications, Admissions and Enrollment in the College Market

I develop and estimate a structural equilibrium model of the college market. Students, having heterogeneous abilities and preferences, make college application decisions, subject to uncertainty and application costs. Colleges, observing only noisy measures of student ability, choose tuition and admissions policies to compete for more able students. Tuition, applications, admissions and enrollment are joint outcomes from a subgame perfect Nash equilibrium. I estimate the structural parameters of the model using data from the National Longitudinal Survey of Youth 1997, via a three-step procedure to deal with potential multiple equilibria. In counterfactual experiments, I use the model first to examine the extent to which college enrollment can be increased by expanding the supply of colleges, and then to assess the importance of various measures of student ability.College market, tuition, applications, admissions, enrollment, discrete choice, market equilibrium, multiple equilibria, estimation

Theory for superconductivity in alkali chromium arsenides A2Cr3As3 (A=K,Rb,Cs)

We propose an extended Hubbard model with three molecular orbitals on a hexagonal lattice with $D_{3h}$ symmetry to study recently discovered superconductivity in A$_2$Cr$_3$As$_3$ (A=K,Rb,Cs). Effective pairing interactions from paramagnon fluctuations are derived within the random phase approximation, and are found to be most attractive in spin triplet channels. At small Hubbard $U$ and moderate Hund's coupling, the pairing arises from 3-dimensional (3D) $\gamma$ band and has a spatial symmetry $f_{y(3x^{2}-y^{2})}$, which gives line nodes in the gap function. At large $U$, a fully gapped $p$-wave state, $p_{z}\hat{z}$ dominates at the quasi-1D $\alpha$-band

Effect of applied DC voltages and temperatures on space charge behaviour of multi-layer oil-paper insulation

In this paper, space charge in a multi-layer oil-paper insulation system was investigated using the pulsed electroacoustic (PEA) technique. A series of measurements had been carried following subjection of the insulation system to different applied voltages and different temperatures. Charge behaviours in the insulation system were analyzed and the influence of temperature on charge dynamics was discussed. The test results shows that homocharge injection takes place under all the test conditions, the applied DC voltage mainly affects the amount of space charge, while the temperature has greater influence on the distribution and mobility of space charge inside oil-paper samples

Equilibrium Tuition, Applications, Admissions and Enrollment in the College Market

I develop and structurally estimate an equilibrium model of the college market. Students, who are heterogeneous in both abilities and preferences, make college application decisions, subject to uncertainty and application costs. Colleges observe only noisy measures of student ability and set up tuition and admissions policies to compete for more able students. The model incorporates tuition, applications, admissions and enrollment as the joint outcome from a subgame perfect Nash equilibrium. I estimate the structural parameters of the model using the NLSY 97 data, via a three-step estimation procedure to deal with potential multiple equilibria. I use the estimated model to perform three counterfactual experiments. First, I explore the impacts of incomplete information on the market. A perfect measure of student ability would lead to higher enrollee ability across colleges and a $2500 increase in average student welfare. Second, I examine the equilibrium consequences of funding cuts to public colleges. All colleges, public and private, increase their tuition, and the drop in student welfare is three times as large as government savings. Finally, I study the extent to which the government can expand college access by increasing the supply of lower-ranked colleges. At most 2.1% more students could be drawn into colleges