Emerging Bond Market Volatility and Country Spreads

Using JPMorgan's emerging market bond index, this paper analyzes how increases in country credit spreads can persist in emerging bond markets. The results of T-GARCH regressions show that, during financial crisis periods, emerging countries' credit spreads may increase persistently as a result of interaction between changes in spreads and volatilities, making emerging bond markets more turbulent. The results suggest that emerging countries should endeavor to develop a stabilization mechanism by enhancing information efficiency in bond markets. In particular, because Asian countries have experienced persistent, overreactive volatility, this paper implies that Asian countries should work together more closely during financial crisis periods.     

The role of stochastic volatility and return jumps: reproducing volatility and higher moments in the KOSPI 200 returns dynamics

This paper investigates the role of stochastic volatility and return jumps in reproducing the volatility dynamics and the shape characteristics of the Korean Composite Stock Price Index (KOSPI) 200 returns distribution. Using efficient method of moments and reprojection analysis, we find that stochastic volatility models, both with and without return jumps, capture return dynamics surprisingly well. The stochastic volatility model without return jumps, however, cannot fully reproduce the conditional kurtosis implied by the data. Return jumps successfully complement this gap. We also find that return jumps are essential in capturing the volatility smirk effects observed in short-term options.

Volatility Relationship between Crude Oil and Petroleum Products

This paper utilizes calculated historical volatility and GARCH models to compare the historical price volatility behavior of crude oil, motor gasoline and heating oil in U.S. markets since 1990. We incorporate a shift variable in the GARCH/TARCH models to capture the response of price volatility to a change in OPEC’s pricing behavior. This study has three major conclusions. First, there was an increase in volatility as a result of a structural shift to higher crude oil prices after April 1999. Second, volatility shocks from current news are not important since GARCH effects dominate ARCH effects in the variance equation. Third, persistence of volatility in all commodity markets is quite transitory, with half-lives normally being a few weeks.

不同的政策不确定性对股市波动影响相同吗?

本文基于多因子混频波动率模型,研究经济政策不确定性对股市行业波动的影响,为预防出现结构性断点,将样本分为经济增长和经济平稳两个时期,分别探讨两个时期内经济政策不确定性对股市波动的影响。研究发现,在全样本时期货币政策不确定性会显著增强行业波动,贸易和外汇政策不确定性会抑制行业波动,而财政政策不确定性的影响存在行业差异性;子样本结果显示,贸易政策不确定性对行业波动的影响存在非对称性,在经济增长期存在助推作用,在经济平稳期存在抑制作用;同时行业波动在经济增长期对贸易政策反应敏感,在经济平稳期对财政政策反应敏感。     

跳跃随机波动的阈值模型风险值的贝叶斯估计

文章基于一类跳跃随机波动的阈值模型风险值估计贝叶斯分析,在给定先验分布下,以马尔科夫链蒙特卡洛方法估计模型中的未知参数,并给出了MCMC模拟算法,进而讨论了风险值的预测。根据模拟结果,我们得知,如果没有考虑金融时间序列的外生冲击导致的跳跃行为,将会高估风险值,因此考虑跳跃行为后,将增加风险值估计的精度。     

基于GARCH族模型对中国股市波动的分析与预测

运用GARCH类模型对沪深300指数序列的波动性、收益率进行了实证研究,并且对序列做了拟合与预测,获得了不错的效果。除此,还证实了中国股市存在着显著的非对称效应。     

基于KMV-Merton模型的上市公司信用风险度量研究

本文结合KMV-Merton模型,对上市公司信用风险度量方法进行比较研究。首先,求得权益收益的条件标准差;其次,通过改进的迭代过程估计KMV-Merton模型中不可观测的资产市值和波动率,进而根据预期违约概率评估上市公司的信用状况,并对两类模型分别得到的违约距离进行了比较分析。     

Biological conservation in dynamic agricultural landscapes: Effectiveness of public policies and trade-offs with agricultural production

Land use change and land management intensification are major drivers of biodiversity loss, especially in agricultural landscapes, that cover a large and increasing share of the world's surface. Incentive-based agri-environmental policies are designed to influence farmers' land-use decisions in order to mitigate environmental degradation. This paper evaluates the effectiveness of agri-environmental schemes for biological conservation in a dynamic agricultural landscape under economic uncertainty. We develop a dynamic ecological economic model of agricultural land-use and spatially explicit population dynamics. We then relate policies (subsidies to grassland, taxation of agricultural intensity) to the ecological outcome (probability of persistence of a species of interest). We also analyze the associated trade-offs between agricultural production (in value) and biological conservation (in probability of persistence) at the landscape scale.     

金融危机后中国股市波动性结构变化测度及其原因分析

以2005年4月至2010年4月我国沪深300指数为研究对象,使用调整后的EGARCH模型,对金融危机前后中国股市的波动性进行研究。结果显示:金融危机发生后中国股市的波动性明显减弱———这与美国股市明显不同,且波动性结构发生了显著性变化,表现为美国股市对中国股市的影响减弱、中国股市波动的持久性增强等。最后,对产生这些变化的原因进行了理论分析,指出金融危机发生后贸易保护主义抬头、刺激性的宏观经济政策出台是中国股市波动性结构变化的可能原因。     

我国畜产品价格波动分析——基于ARCH类模型

运用ARCH类模型对我国主要畜产品的价格波动率进行了分析。结果表明:牛肉、羊肉和鸡肉的价格波动具有显著的波动积聚性,鸡蛋价格波动没有显著的异方差效应;除牛肉市场外,羊肉和鸡肉市场不具有高风险、高回报的特征;猪肉、牛肉、羊肉和鸡肉的价格波动没有非对称性。认为应在畜产品市场出现大的价格波动时及时采取平抑措施,且政府需规范畜产品市场秩序、完善畜产品市场制度。