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Ultra-thin Pb films with magic thicknesses of 2 monolayer (ML), 4 ML and 6 ML were prepared of atomically flat on the substrate of Si(111)-α-√3 × √3 (or SIC phase) at 145 K. Their surface morphologies and stability were studied by low temperature scanning tunneling microscopy and...
Persistent link: https://www.econbiz.de/10011011149
We have studied the superconductivity of Pb ultra-thin films with thickness from 1 monolayer (ML) to 7 ML grown on Si(111) by molecular beam epitaxy. In situ low temperature scanning tunneling spectroscopy (STS) and angle-resolved photoemission spectroscopy (ARPES) measurements were performed on...
Persistent link: https://www.econbiz.de/10008863955
Persistent link: https://www.econbiz.de/10005382258
This paper proposes to reexamine the trade effect of GATT/WTO based on non-parametric econometric techniques. Our estimation framework uses the simplest gravity model that explains bilateral trade volumes with country sizes and trade resistance, without imposing parametric assumptions typically...
Persistent link: https://www.econbiz.de/10011124073
<Para ID="Par1">For a linear regression model subject to left-truncation and right-censoring where the truncation and censoring points are known constants (or always observed if random), Karlsson and Laitila (Stat Probab Lett 78:2567–2571, <CitationRef CitationID="CR3">2008</CitationRef>) proposed a semiparametric estimator which deals with...</citationref></para>
Persistent link: https://www.econbiz.de/10011241006
In a sample-selection model with the ‘selection’ variable Q and the ‘outcome’ variable Y∗, Y∗ is observed only when Q=1. For a treatment D affecting both Q and Y∗, three effects are of interest: ‘participation’ (i.e., the selection) effect of D on Q, ‘visible performance’...
Persistent link: https://www.econbiz.de/10011052193
In estimating the effect of an ordered treatment τ on a count response y with an observational data where τ is self-selected (not randomized), observed variables x and unobserved variables &epsiv; can be unbalanced across the control group (τ = 0) and the treatment groups (τ = 1, …, J). While...
Persistent link: https://www.econbiz.de/10005764780
This paper reviews six approaches to binary response (y<sub>1</sub>) structural forms with an endogenous regressor y<sub>2</sub>: (i) the two-stage least squares estimator-like substitution approach, (ii) the control function approach, (iii) the system reduced-form approach, (iv) the artificial instrumental regressor...
Persistent link: https://www.econbiz.de/10011153347
Rose (2004) showed that the WTO or its predecessor, the GATT, did not promote trade, based on conventional econometric analysis of gravity-type equations of trade. We argue that conclusions regarding the GATT/WTO trade effect based on gravity-type equations are arbitrary and subject to...
Persistent link: https://www.econbiz.de/10005006756
We investigate whether TV watching at ages 6-7 and 8-9 affects cognitive development measured by math and reading scores at ages 8-9 using a rich childhood longitudinal sample from SY79. Dynamic panel data models are estimated to handle the unobserved child-specific factor, endogeneity of TV...
Persistent link: https://www.econbiz.de/10005006769