Excess noise measurement in In0.53Ga0.47As

The excess noise due to impact ionization has been measured explicitly for the first time in In/sub 0.53/Ga/sub 0.47/As. By using a phase sensitive detection technique, the noise due to avalanche current was determined even in the presence of high tunneling currents. The excess noise due to pure electron injection measured on a series of thick In/sub 0.53/Ga/sub 0.47/As p/sup +/-i-n/sup +/ diodes suggests large electron to hole ionization coefficient ratio between 3.7 at electric field of 310 kV/spl middot/cm/sup -1/ to 5.3 at 260 kV/spl middot/cm/sup -1/. Excess noise was also measured at fields as low as 155 kV/spl middot/cm/sup -1/ suggesting that significant impact ionization occurs at these low fields. The multiplication and excess noise calculated using published ionization coefficients and ignoring dead space effects, gave good agreement with the experimental data for mixed and pure electron injection

Corruption and International Valuation: Does Virtue Pay?

Using firm-level data from 44 countries, we investigate the relation between corruption and international corporate values. Our analysis shows that firms from more corrupt countries trade at significantly lower market multiples. The effect is both economically and statistically significant. Furthermore, using a two-stage estimation procedure, we show that corruption impacts firm value primarily through lower expected future cash flows, most directly captured by firms’ profitability forecasts. Collectively, our evidence shows corruption has significant economic consequences for shareholder value.corruption; international valuation; market multiple

Strategies to improve retention of postgraduate business students in distance education courses: an Australian case

In spite of the clear value of postgraduate business students to many providers of distance education courses, the factors affecting the retention of these students have received limited attention in the literature. In addressing this gap, this paper presents the findings of a qualitative study into the factors affecting the retention of postgraduate business students at a major Australian distance education university. The findings of this study suggest that a range of situational, dispositional and attitudinal factors impact upon student retention on this context, both as enablers of and obstacles to ongoing participation. In many cases, these factors differ to those identified in the existing literature on student retention. Based on these findings, we present a range of strategies designed to improve the retention of postgraduate business students by maximising enabling factors and minimising the impact of any identified obstacles. Limitations of the study and suggestions for further research are also presented

Is Unlevered Firm Volatility Asymmetric?

Asymmetric volatility refers to the stylized fact that stock volatility is negatively correlated to stock returns. Traditionally, this phenomenon has been explained by the financial leverage effect. This explanation has recently been challenged in favor of a risk premium based explanation. We develop a new, unlevering approach to document how well financial leverage, rather than size, beta, book-to-market, or operating leverage, explains volatility asymmetry on a firm-by-firm basis. Our results reveal that, at the firm level, financial leverage explains much of the volatility asymmetry. This result is robust to different unlevering methodologies, samples, and measurement intervals. However, we find that financial leverage does not explain index-level volatility asymmetry, which is consistent with theoretical results in Aydemir, Gallmeyer and Hollifield (2006).Volatility asymmetry, Financial leverage, Financial Economics, Research Methods/ Statistical Methods, G12,