Addressing the Low Returns to Education of African Born Immigrants in the United States

This paper uses 2000 Census 5 percent Public Use Microdata Sample to investigate the relative earning pattern of immigrants from African countries, and explores the relevance of existing explanations of the low returns to education. The study uses the Extreme Bound Analysis to check the robustness of the variables of interests. The empirical findings from the conventional earnings regression conform to the theoretical expectations. However, not all the variables of interests are robust in Extreme Bound Analysis. This suggests that conventional specifications may not encompass all necessary information. Future study may explicitly controls for more detailed country-specific characteristics of the immigrant-sending countries

The Effects of Finger-Walking in Place (FWIP) on Spatial Knowledge Acquisition in Virtual Environments

Spatial knowledge, necessary for efficient navigation, comprises route knowledge (memory of landmarks along a route) and survey knowledge (overall representation like a map). Virtual environments (VEs) have been suggested as a power tool for understanding some issues associated with human navigation, such as spatial knowledge acquisition. The Finger-Walking-in-Place (FWIP) interaction technique is a locomotion technique for navigation tasks in immersive virtual environments (IVEs). The FWIP was designed to map a human’s embodied ability overlearned by natural walking for navigation, to finger-based interaction technique. Its implementation on Lemur and iPhone/iPod Touch devices was evaluated in our previous studies. In this paper, we present a comparative study of the joystick’s flying technique versus the FWIP. Our experiment results show that the FWIP results in better performance than the joystick’s flying for route knowledge acquisition in our maze navigation tasks

From a Mirage to an Oasis: Narcissism, Perceived Creativity, and Creative Performance

We examine the link between narcissism and creativity at the individual, relational, and group levels of analysis. We find that narcissists are not necessarily more creative than others but they think they are, and they are adept at convincing others to agree with them. In the first study, narcissism was positively associated with self-rated creativity, despite the fact that blind coders saw no difference between the creative products offered by those low and high on narcissism. In a second study, more narcissistic individuals asked to pitch creative ideas to a target person were judged by the targets as being more creative than were less narcissistic individuals, in part because narcissists were more enthusiastic. Finally, in a study of group creativity, we find evidence of a curvilinear effect: having more narcissists is better for generating creative outcomes (but having too many provides diminishing returns)

The Expansion of College Education in the United States: Is There Evidence of Declining Cohort Quality?

This paper documents the expansion of college education in the U.S. and examines to what extent the increase in the number of college graduates may have lead to a decline in the average quality of college graduates. Using the 1940-1990 Census, we compare across birth year cohorts with varying levels of college completion. We find some weak evidence that college graduate men from highly educated cohorts earn a relatively smaller wage premium even controlling for the relative supply effect. However, these cohort quality effects account for only a small fraction of the recent fluctuation in the college wage premium.

More on heavy tetraquarks in lattice QCD at almost physical pion mass

We report on our progress in studying exotic, heavy tetraquark states, $qq\prime \bar Q\bar Q\prime$. Using publicly available dynamical $n_f =2+1$ Wilson-Clover gauge configurations, generated by the PACS-CS collaboration, with pion masses $\simeq$164, 299 and 415 MeV, we extend our previous analysis to heavy quark components containing heavier than physical bottom quarks $\bar Q\bar Q\prime=\bar b\prime\bar b\prime$ or $\bar Q\bar Q\prime=\bar b\bar b\prime$, charm and bottom quarks $\bar c\bar b$ and also only charm quarks $\bar c\bar c$. Throughout we employ NRQCD and relativistic heavy quarks for the heavier than bottom, bottom and charm quarks. Using our previously established diquark-antidiquark and meson-meson operator basis we comment in particular on the dependence of the binding energy on the mass of the heavy quark component $\bar Q\bar Q$, with heavy quarks ranging from $m_Q=0.85\ldots 6.3\cdot m_b$. In the heavy flavor non-degenerate case, $\bar Q\bar Q\prime$, and especially for the tetraquark channel $ud\bar c\bar b$, we extend our work to utilize a $3\times 3$ GEVP to study the ground and threshold states thereby enabling a clear identification of possible binding. Finally, we present initial work on the $\bar Q\bar Q\prime=\bar c\bar c$ system where a much larger operator basis is available in comparison to flavor combinations with NRQCD quarks.Comment: 8 pages, 5 figures, proceedings contribution to "Lattice 2017. 35th International Symposium on Lattice Field Theory", 18th-24th June 2017, Granada, Spai

Evidence for charm-bottom tetraquarks and the mass dependence of heavy-light tetraquark states from lattice QCD

We continue our study of heavy-light four-quark states and find evidence from lattice QCD for the existence of a strong-interaction-stable $I(J^P)=0(1^+)$ $ud\bar{c}\bar{b}$ tetraquark with mass in the range of 15 to 61 MeV below $\bar{D}B^*$ threshold. Since this range includes the electromagnetic $\bar{D}B\gamma$ decay threshold, current uncertainties do not allow us to determine whether such a state would decay electromagnetically, or only weakly. We also perform a study at fixed pion mass, with NRQCD for the heavy quarks, simulating $qq^\prime \bar{b}^\prime \bar{b}$ and $q q^\prime \bar{b}^\prime\bar{b}^\prime$ tetraquarks with $q,\, q^\prime =ud$ or $\ell s$ and variable, unphysical $m_{b^\prime}$ in order to investigate the heavy mass-dependence of such tetraquark states. We find that the dependence of the binding energy follows a phenomenologically-expected form and that, though NRQCD breaks down before $m_{b^\prime}=m_c$ is reached, the results at higher $m_{b^\prime}$ clearly identify the $ud\bar{b}^\prime \bar{b}$ channel as the most likely to support a strong-interaction-stable tetraquark state at $m_{b^\prime}=m_c$. This observation serves to motivate the direct $ud\bar{c}\bar{b}$ simulation. Throughout we use dynamical $n_f=2+1$ ensembles with pion masses $m_\pi=$415, 299, and 164 MeV reaching down almost to the physical point, a relativistic heavy quark prescription for the charm quark, and NRQCD for the bottom quark(s).Comment: 24 pages, 4 figure

A 55-Year-Old Man With Rapid Onset Rectosigmoid Mass and Hepatic Metastases with an AFP of \u3e 3 Million ng/mL

Case A 55-year-old male with a past medical history of ulcerative colitis diagnosed in 1999, Barrett’s esophagus, hyperlipidemia, and diabetes mellitus presented with a 2-week duration of daily constant abdominal pain. He described the pain as a sharp, epigastric pain not worsened with food intake or bowel movements. He was unable to tolerate any oral intake for a week prior to admission secondary to increased epigastric pain. He stated an increase in bowel movements to 1 per day that was softer and less formed than usual. He also stated he had a near syncopal episode on the day of admission and reported dizziness. The patient denied any bright red blood per rectum or having dark stools. He states he also had some fevers, chills, and a sore throat for 3 days duration. He had tried some Pepto Bismol without any improvement

Essays on foreign currency risk management

This dissertation studies on-balance-sheet and off-balance-sheet foreign currency risk management of corporate firms and commercial banks. It is comprised of two essays. The first essay investigates what determines firms’ foreign currency spot net asset positions, derivatives hedging and synthetic hedging positions. We build a model that anticipates a firm’s market timing in currency markets and credit markets according to the exchange-rate return and interest rate differential. Using a unique set of data containing complete foreign currency spot and derivatives positions of Korean exporting firms, we empirically find that currency position-squaring firms have significantly higher firm value. We also find evidence that these firms time the currency market when they manage their currency cash position. Meanwhile, firms time the credit market when they determine the use of foreign currency debts. Strikingly, firms still time the market even when they conduct derivatives hedging and synthetic hedging. Our findings are consistent with the market timing theory of capital structure. The second essay examines what determines banks’ exposure to foreign currency risks, their management of these risks, and the relationship to the probability of bank failures. Using a unique data set of Korean banks with detailed information on their foreign currency risk exposures and hedging positions, we find that banks’ foreign currency position mismatches, maturity mismatches, and debt roll-over risks are significantly attributed to their dollar carry lending strategy, which is stimulated by market timing of corporate firms, short-maturity dollar borrowings, real estate market booms, and dollar interest rate tightening. We also find that banks’ foreign currency exposures significantly increase their financial distress likelihood through dollar carry lending activities. Finally we show that, overall, banks that better match their foreign currency positions and maturities are rewarded with lower probabilities of financial distress