Suchergebnisse

"We develop a sequential procedure to test the adequacy of jump-diffusion models for return distributions. We rely on intraday data and nonparametric volatility measures, along with a new jump detection technique and appropriate conditional moment tests, for assessing the import of jumps and leverage effects. A novel robust-to-jumps approach is utilized to alleviate microstructure frictions for realized volatility estimation. Size and power of the procedure are explored through Monte Carlo methods. Our empirical findings support the jump-diffusive representation for S&P500 futures returns but reveal it is critical to account for leverage effects and jumps to maintain the underlying semi-martingale assumption"--National Bureau of Economic Research web site

Petros Iosifidis investigates the challenges that Public Television (PTV) broadcasters in Western European countries encounter in a competitive digital broadcasting environment and looks at the policies and strategies that these broadcasters are adopting in order to remain accountable, competitive and efficient. By looking at a number of large and small PTV broadcasters, the book reveals the different policies and strategy patterns that exist across Europe and uses European experience to propose workable strategies to be adopted by national PTV broadcasters

Several recent education reform measures, including the federal No Child Left Behind Act (NCLB), couple school choice with accountability measures to allow parents of children in under-performing schools the opportunity to choose higher-performing schools. We use the introduction of NCLB in the Charlotte-Mecklenburg School District to determine if the choice component had an impact on the schools parents chose and if those changed choices led to academic gains. We find that 16% of parents responded to NCLB notification by choosing schools that had on average 1 standard deviation higher average test scores than their current NCLB school. We then use the lottery assignment of students to chosen schools to test if changed choices led to improved academic outcomes. On average, lottery winners experience a significant decline in suspension rates relative to lottery losers. We also find that students winning lotteries to attend substantially better (above-median) schools experience significant gains in test scores. Because proximity to high-scoring schools drives both the probability of choosing an alternative school and the average test score at the school chosen, our results suggest that the availability of proximate and high-scoring schools is an important factor in determining the degree to which school choice and accountability programs can succeed at increasing choice and immediate academic outcomes for students at under-performing schools.

In the past few decades, some measures of population risk have improved, while others have deteriorated. Understanding the health of the population requires integrating these different trends. We compare the risk factor profile of the population in the early 1970s with that of the population in the early 2000s and consider the impact of a continuation of recent trends. Despite substantial increases in obesity in the past three decades, the overall population risk profile is healthier now than it was formerly. For the population aged 25-74, the 10 year probability of death fell from 9.8 percent in 1971-75 to 8.4 percent in 1999-2002. Among the population aged 55-74, the 10 year risk of death fell from 25.7 percent to 21.7 percent. The largest contributors to these changes were the reduction in smoking and better control of blood pressure. Increased obesity increased risk, but not by as large a quantitative amount. In the future, however, increased obesity may play a larger role than continued reductions in smoking. We estimate that a continuation of trends over the past three decades to the next three decades might offset about a third of the behavioral improvements witnessed in recent years.