Comparison of asymmetric stochastic volatility models under different correlation structures

This paper conducts simulation-based comparison of several stochastic volatility models with leverage effects. Two new variants of asymmetric stochastic volatility models, which are subject to a logarithmic transformation on the squared asset returns, are proposed. The leverage effect is introduced into the model through correlation either between the innovations of the observation equation and the latent process, or between the logarithm of squared asset returns and the latent process. Suitable Markov Chain Monte Carlo algorithms are developed for parameter estimation and model comparison. Simulation results show that our proposed formulation of the leverage effect and the accompanying inference methods give rise to reasonable parameter estimates. Applications to two data sets uncover a negative correlation (which can be interpreted as a leverage effect) between the observed returns and volatilities, and a negative correlation between the logarithm of squared returns and volatilities.     

娱乐文化产业对美国经济增长贡献的实证分析

娱乐文化产业的定义众说纷纭。娱乐文化产业关注市场经济中的艺术、文化、娱乐及许多其他类型的活动。本文主要考察娱乐文化产业的其中一个方面,即其对经济的影响。之前也有学者探讨过这个问题,而本文笔者从官方数据出发,指出1995年娱乐文化产业为美国带来了2510亿美元的经济效益,而到2004年时,这一数字已经达到5650亿美元。     

State of public relations education in the United States: 2006 report on a national survey of executives and academics

A survey of 312 public relations executives and educators examined how well practitioners and instructors perceive public relations students to be prepared for the practice, the content and value of public relations curricula and, the future of public relations education in the United States. Results are largely consistent with those from a slightly smaller 1998 survey, suggesting that the views of both groups are consistent over time and providing the first two data points in what it is hoped will develop into a longitudinal line of research addressing public relations education. Judgments regarding the desired characteristics among job applicants and essential curriculum content were extremely similar between the practitioner and educator groups with both wanting more emphasis on research, ethics and strategic planning as the field moves from a low-paid technical emphasis toward a much better paid strategic planning and research emphasis.     

MINORITY CONCENTRATION, DISADVANTAGE, AND INEQUALITY IN THE NONMETROPOLITAN UNITED STATES

The implications of the residential concentration of minority populations are issues of vital concern in the United States. Much of the previous minority concentration literature has focused on African-American residents of metropolitan communities. This article expands on this literature by exploring a variety of minority groups in nonmetropolitan communities. It was found that the minority residents of communities with large minority populations were in worse socioeconomic conditions than the minority residents of predominately white communities. Further, for most socioeconomic variables, it was found that as minority concentration increased, white residents tended to do better. In addition, the extent of racial inequality between minority and white residents was greater in communities with larger minority populations. Implications of the above findings are discussed.     

The Correlates of Farm Concentration in American Agriculture

Abstract In recent years, the most pronounced change in the structure of American agriculture has been the increasing concentration of farm production. A human ecological perspective was used to generate hypotheses about the factors related to variations in farm concentration in U.S. counties. Analysis using the 1978 and 1987 Censuses of Agriculture revealed that concentration is greatest in counties with higher levels of agricultural intensity, greater use of mechanization, and greater use of farm labor.     

Provision of hepatitis C education in a nationwide sample of drug treatment programs

Hepatitis C virus (HCV) has reached epidemic proportions among drug users, and drug programs are in a unique position to provide each of their patients with HCV education. Using a nationwide sample (N = 434) of drug treatment programs, we report the results of a logistic regression analysis that differentiates programs providing HCV education to all of their patients versus programs that do not. Fifty-four percent of the programs provide HCV education to all of their patients. Programs are about four and a half times as likely to provide HCV education to all patients if they dispense methadone; almost four times as likely to provide this service if they educate most of their staff about HCV; twice as likely if they are residential; and almost twice as likely if they conduct HIV testing on-site. Our findings indicate that there is a need to increase HCV educational services in drug treatment programs.