481 research outputs found
Analyzing the link between real exchange rate and productivity
This paper study, in panel data, the relationship between real exchange rate and total factor productivity on a sample of 68 developed and developing countries for the period 1960-1999. The theoretical part presents the arguments advanced to explain the effects of real exchange rate on productivity, technical efficiency and technological progress. The productivity is obtained as a Solow residual of an estimation of a Cobb-Douglas stochastic production function frontier. The results show that an exchange rate appreciation causes an increase of total factor productivity. The results also illustrates that this effect of real exchange rate on productivity is non linear: threshold effect. Below the threshold exchange rate reacts negatively on productivity while above the threshold it acts positively. Robustness analysis demonstrates that these results hold both in subsamples of developed and developing countries.O11, O16, O47
Exchange Rate Volatility and Investment, A Panel Data Cointegration Approach
This paper examines the link between the real exchange rate volatility and domestic investment by using the panel data cointegration techniques. In the first part of the paper, we study the theoretical link between the exchange rate, its volatility and the investment in a small open economy. The model shows that the effects of exchange rate volatility on investment are nonlinear. In the second part, we examine the empirical link between the exchange rate volatility and the investment. The results illustrate that the exchange rate volatility has a strong negative impact on investment. This outcome is robust in low income and middle income countries, and by using an alternative measurement of exchange rate volatilityExchange rate volatility; Investment; Appreciation; Depreciation; Panel data cointegration; Dynamic Optimization; Capital goods; Expectations
The effects of real exchange rate volatility on productivity growth
This paper employs panel data instrumental variable regression and threshold effect estimation methods to study the link between real effective exchange rate volatility and total factor productivity growth on a sample of 74 countries on six non overlapping sub-periods spanning in total from 1975 to 2004. The results illustrate that real effective exchange rate volatility affects negatively total factor productivity growth. But this effect is not very high. This outcome is corroborated by estimations using an alternative measurement of real effective exchange rate volatility and on a subsample of developed countries. But for developing countries the negative effect of real effective exchange rate volatility is very large. We also found that real effective exchange rate volatility acts on total factor productivity according to the level of financial development. For very low and very high levels of financial development, real exchange rate volatility has no effect on productivity growth but for moderately financially developed countries, real exchange rate volatility reacts negatively on productivity.real effective exchange rate; volatility; total factor productivity growth; panel data instrumental variable regression; threshold effect estimation; stochastic frontier analysis
The effects of real exchange rate misalignment and real exchange volatility on exports
This paper uses panel data cointegration techniques to study the impacts of real exchange rate misalignment and real exchange rate volatility on total exports for a panel of 42 developing countries from 1975 to 2004. The results show that both real exchange rate misalignment and real exchange rate volatility affect negatively exports. The results also illustrate that real exchange rate volatility is more harmful to exports than misalignment. These outcomes are corroborated by estimations on subsamples of Low-Income and Middle-Income countries.real effective exchange rate; misalignment; volatility; exports; pooled mean group estimator
UNCOVERING BASIC WANTS USING THE ROTTERDAM AND AIDS MODELS: THE US HOUSEHOLD ENERGY CONSUMPTION CASE
Economists inflate the explanatory power of measurable variables such as price and income to explain demand. Using only quantifiable variables is very attractive since it makes it easy to construct mathematically consistent and well expressed models. However, since Lancaster (1971), economic awareness has increased to such a degree that latent, hardly observable and/or measurable variables may bring more insight to the demand analysis. Two approaches compete to introduce such variables: an economic approach originally developed by Lancaster and Becker (1965), and a statistical approach. For Lancaster, beyond quantities of goods demanded, the characteristics of goods are what shape consumer utility and consequently determine its choice. This approach is theoretical and largely based on economic intuition. Few empirical studies using Lancaster have been successful so far. The second, purely statistical approach, considers the possibility of transforming observed data to obtain the "basic wants" that truly affect consumer choice. This approach, known as the Preference Independence Transformation (PIT), has so far been applied only in a few studies using the Rotterdam model frame. The PIT was certainly deduced through mathematically thorough and consistent analysis to uncover the basic want, denoted as T-goods. We intend to revisit the PIT under the Rotterdam framework to uncover the basic goods. Alongside, we implement --for the first time--an independent transformation that eliminates the Slusky interdependencies from the Almost Ideal Demand System (AIDS) setting. We will refer to it as the Slutsky Matrix Independent Transformation (SMIT). Regarding our purpose to check if the two techniques identically define the basic goods, the findings were not conclusive. As a result, we further the analysis by introducing a possibility to unveil the basic wants using US household data
Analysis of defects in GaN using Hybrid Density Functional Theory
In this thesis, we first present a brief overview of various theoretical approaches used to examine the electronic structure of defects in GaN. Using the recently developed hybrid density functional theory (HSE06) along with the experimental measurements, we propose a new explanation of the nature of the yellow luminescence band in carbon-doped GaN. We conduct a systematic study of electronic and optical properties of defects (Carbon, Oxygen, Silicon related) that are candidates for the origin of yellow luminescence. We show that the CN-ON complex is significantly more likely to form compared to isolated carbon configurations. In contrast to the properties of the isolated carbon acceptor, calculated defect levels and optical transitions involving deep level of the CN-ON complex agree quite well with our thermal luminescence quenching data as well as with the experimentally measured C-doped GaN luminescence spectra. Hence, the CN-ON complex, rather than isolated C impurity, is more likely to resolve a long-standing problem of the yellow luminescence in GaN
Capture of Tacit Knowledge through Storytelling
This project introduces storytelling as a mechanism to capture tacit knowledge believed to be an experience- based knowledge. Storytelling is a mechanism through which tacit knowledge is captured. This project provides a bridge and a platform that will allow the capture of tacit knowledge in a structured method.
The objective of this project is to develop a knowledge management system that captures tacit knowledge using storytelling. Throughout this project we will attempts to capture, store, retrieve, and transfer and / or share knowledge within an entity
Obstetrical complications among adolescent girls at the maternity ward of Ignace Deen National Hospital
Background: The objective of this study was to highlight obstetrical complications that occurred among adolescent girls who delivered at the ward and to identify factors associated with the occurrence of such complications.Methods: This was a prospective study of descriptive and analytical type extending over a period of one year from September 1, 2016 to August 31, 2017 carried out at the maternity ward of Ignace Deen National Hospital at Conakry Teaching Hospital (CHU). It covered a continuous series of 1034 deliveries among adolescent girls.Results: The frequency of childbirth among adolescent girls was 16.7%. The main complications identified were dystocia, severe preeclampsia, eclampsia, retroplacental hematoma, placenta previa, uterine rupture, severe anemia, postpartum hemorrhage and puerperal endometritis. These complications occurred among adolescent girls aged 18 to 19, christian, skin and pelvic bones secondary school or university students. Factors associated with such complications were the marital status (p=0.010), the gestational age (p=0.012), the number of prenatal consultations (p=0.001), the place of prenatal consultation (p=0.001), the reason for admission (p=0.000) and the mode of admission (p=0.000).Conclusions: Childbirth among adolescent girls is frequent in this context; complications are numerous but they are preventable in the vast majority of cases
Theoretical and Experimental Analysis of Optical Properties of Defects in GaN:
Using the Heyd-Scuseria-Ernzherof (HSE06) hybrid functional method along with photoluminescence experimental measurements, we analyze the properties of intrinsic defects such as vacancies, interstitials, antisites, and common complexes. By using configurational coordinate diagrams, we estimate the likelihood of defects to be radiative or non-radiative. Our calculations show that gallium vacancies exhibit a large magnetic moment in the neutral charge state and are most likely non-radiative. We also investigate the correlation between the observed infrared PL bands created in 2.5 MeV electron-irradiated GaN samples and the formation of native defects. It is found that gallium-nitrogen divacancies are possible sources of the broad PL band peaking at 0.95 eV while interstitial gallium is likely to be responsible for the narrow infrared PL band centered around 0.85 eV, with a phonon fine structure at 0.88 eV.
In addition to native defects, we also investigate the blue luminescence band (BL2) peaking at 3.0 eV that is observed in high-resistivity GaN samples. Under extended ultraviolet (UV) light exposure, the BL2 band transforms into the yellow luminescence (YL) band with a maximum at 2.2 eV. Our calculations suggest that the BL2 band is related to a hydrogen-carbon defect complex, either CNON-Hi or CN-Hi. The complex creates defect transition level close to the valence band, which is responsible for the BL2 band. Under UV illumination, the complex dissociates, leaving as byproduct the source of the YL band (CNON or CN) and interstitial hydrogen.
In conclusion, theoretical predictions of thermodynamic and optical transitions of defects in GaN via the HSE06 method, are found to be within less than 0.2 eV when compared to experiment. Hence the HSE formalism is a powerful tool for the identification and characterization of defects responsible for observed PL bands in GaN
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