Inequality in the work visa approvals of U.S. immigrants

Thesis (S.M. in Management Research)--Massachusetts Institute of Technology, Sloan School of Management, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (p. 38-43).This study examines how U.S. immigration policies, as implemented by agents acting on behalf of the federal government, shape migration and key employment outcomes of skilled foreign nationals. Using a unique dataset, which encompasses the entire population of 1,441,856 H-1B temporary work visa requests evaluated by government agents from May 2005 to April 2010, I assess whether agents' visa approval and denial decisions are shaped by immigrants' sending country characteristics. Through this program, government agents mediate a key institutional boundary: access to the U.S. labor market, by conferring or withholding "current" legal standing to potential immigrants. Controlling for important application evaluation criteria, I find that immigrant workers from sending countries with lower levels of economic development are less likely to receive approvals for initial and continuing employment requests, all else equal. Government agents' visa approvals may also shape career mobility among those immigrants previously granted legal standing through the evaluation of requests to change jobs or employers. In these evaluations, however, sending country level of economic development is not a statistically significant predictor of approval. The paper concludes by discussing the implications of these findings for theories of inequality and labor market mobility, in addition to practical considerations regarding the efficient and fair administration of immigration policy.by Ben A. Rissing.S.M.in Management Researc

Graduates of Character - Values and Character: Higher Education and Graduate Employment

Graduates of Character is the product of an empirical enquiry into the values, virtues, dispositions and attitudes of a sample of students and employees who volunteered to be involved. The research team sought host sites which would offer a diverse set of interviewees in gender, ethnicity, religion and aspiration. In this study we discuss what character is taken to mean by students and employees in their years of higher education and employment. We examine what their values are, what they gain from the university, what they believe employers look for when recruiting, what they hope to give to an employer, and what they expect from their employer. We then explore who or what influenced their values and moral development. We also examined the role of the personal tutor or mentor, and the persons or services to which they might go for personal and/or professional support

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The Occupational Status Of Physical Education Graduates Of Prairie View College From 1942-1952

According to the belief of many of our administrators, Physical Education is playing , and it can be done at recess with a teacher appointed to watch over the play period. This was changed by the State Department of Texas, requiring one-fourth unit per semester for graduation from High School. Trained personnel had to be brought in with as many as twelve hours of training to teach Physical Education. Prairie View A. & M. College set up its Physical Education Department requiring thirty-two hours in Physical Education for a major and twenty hours for a minor in the field. Occupations are eliminated from the world of work, in the twinkling of an eye; from scientific laboratories, new vocations are constantly called into being. The nation, due to these enlightening changes, has become a neighborhood with common interests. Unemployment, once a crime, but now the concern of all, has to be even in times of prosperity - our most significant social problem. Yet, despite all these changes, social and economic, the responsibility remains with every individual to select an occupation and prepare for it. But due to the complexity of the task, and the lack of a background of experience from which to borrow, we become confused

Parameter Redundancy with Applications in Statistical Ecology

This thesis is concerned with parameter redundancy in statistical ecology models. If it is not possible to estimate all the parameters, a model is termed parameter redundant. Parameter redundancy commonly occurs when parameters are confounded in the model so that the model could be reparameterised in terms of a smaller number of parameters. In principle, it is possible to use symbolic algebra to determine whether or not all the parameters of a certain ecological model can be estimated using classical methods of statistical inference. We examine a variety of different ecological models: We begin by exploring models based on marking a number of animals and observing the same animals at future time points. These observations can either be when the animal is marked and then recovered dead in mark-recovery modelling, or when the animal is marked and then recaptured alive in capture-recapture modelling. We also explore capture-recapture-recovery models where both dead recoveries and alive recaptures can be observed in the same study. We go on to explore occupancy models which are used to obtain estimates of the probability of presence, or absence, for living species by the use of repeated detection surveys, where these models have the advantage that individuals are not required to be marked. A variety of different occupancy models are examined included the addition of season-dependent parameters, group-dependent parameters and species-dependent, along with other models. We investigate parameter redundancy by deriving general results for a variety of different models where the model's parameter dependencies can be relaxed suited to different studies. We also analyse how the results change for specific data sets and how sparse data influence whether or not a model is parameter redundant using procedures written in Maple. This theory on parameter redundancy is vital for the correct use of these ecological models so that valid statistical inference can be made

Strong tip-sample coupling in thermal radiation scanning tunneling microscopy

We analyze how a probing particle modifies the infrared electromagnetic near field of a sample. The particle, described by electric and magnetic polarizabilities, represents the tip of an apertureless scanning optical near-field microscope (SNOM). We show that the interaction with the sample can be accounted for by ascribing to the particle dressed polarizabilities that combine the effects of image dipoles with retardation. When calculated from these polarizabilities, the SNOM signal depends only on the fields without the perturbing tip. If the studied surface is not illuminated by an external source but heated instead, the signal is closely related to the projected electromagnetic local density of states (EM-LDOS). Our calculations provide the link between the measured far-field spectra and the sample's optical properties.We also analyze the case where the probing particle is hotter than the sample and evaluate the impact of the dressed polarizabilities on near-field radiative heat transfer. We show that such a heated probe above a surface performs a surface spectroscopy, in the sense that the spectrum of the heat current is closely related to the local electromagnetic density of states. The calculations agree well with available experimental data.Comment: Soumis \`a JQSRT. arXiv admin note: substantial text overlap with arXiv:1201.483

A proof of completeness for continuous first-order logic

The primary purpose of this article is to show that a certain natural set of axioms yields a completeness result for continuous first-order logic. In particular, we show that in continuous first-order logic a set of formulae is (completely) satisfiable if (and only if) it is consistent. From this result it follows that continuous first-order logic also satisfies an \emph{approximated} form of strong completeness, whereby $\Sigma\vDash\varphi$ (if and) only if \Sigma\vdash\varphi\dotminus 2^{-n} for all $n<\omega$. This approximated form of strong completeness asserts that if $\Sigma\vDash\varphi$, then proofs from $\Sigma$, being finite, can provide arbitrary better approximations of the truth of $\varphi$

Terahertz electron-hole recollisions in GaAs/AlGaAs quantum wells: robustness to scattering by optical phonons and thermal fluctuations

Electron-hole recollisions are induced by resonantly injecting excitons with a near-IR laser at frequency $f_{\text{NIR}}$ into quantum wells driven by a ~10 kV/cm field oscillating at $f_{\text{THz}} = 0.57$ THz. At $T=12$ K, up to 18 sidebands are observed at frequencies $f_{\text{sideband}}=f_{\text{NIR}}+2n f_{\text{THz}}$, with $-8 \le 2n \le 28$. Electrons and holes recollide with total kinetic energies up to 57 meV, well above the $E_{\text{LO}} = 36$ meV threshold for longitudinal optical (LO) phonon emission. Sidebands with order up to $2n=22$ persist up to room temperature. A simple model shows that LO phonon scattering suppresses but does not eliminate sidebands associated with kinetic energies above $E_{\text{LO}}$.Comment: 5 pages, 4 figure

First-principles investigations of the magnetic phase diagram of Gd1−x_{1-x}Cax_{x}MnO3_{3}

We studied for the first time the magnetic phase diagram of the rare-earth manganites series Gd$_{1-x}$Ca$_{x}$MnO$_{3}$ (GCMO) over the full concentration range based on density functional theory. GCMO has been shown to form solid solutions. We take into account this disordered character by adapting special quasi random structures at different concentration steps. The magnetic phase diagram is mainly described by means of the magnetic exchange interactions between the Mn sites and Monte Carlo simulations were performed to estimate the corresponding transition temperatures. They agree very well with recent experiments. The hole doped region $x<0.5$ shows a strong ferromagnetic ground state, which competes with A-type antiferromagnetism at higher Ca concentrations $x>0.6$.Comment: Submitted to PR