沪深股市投机泡沫存在性检验的新视角——基于向量误差修正模型的MTAR协整分析

本文通过分析沪证和深证指数及与股票市场密切相关的国民经济运行变量的时间序列,建立向量自回归(VAR)模型,并在此基础上得出了我国股市与经济运行之间的长期均衡关系和短期变动的向量误差修正(VEC)模型。因此引入惯性门限自回归(MTAR)模型,通过检验协整残差的非对称调整假设,对我国股票市场发展是否存在泡沫现象进行进一步分析。针对崔畅等(2006)、王薛等(2008)运用MTAR协整检验对中国股市进行实证研究的MTAR模型平稳性的检验提出了质疑,并用同样的方法以新的视角对沪深股市泡沫重新进行了协整检验,得出了一些结论。

基于MTAR模型的沪市周期性爆炸泡沫检验

我国股市存在理性泡沫得到了普遍认同.但在现实市场中,股市不存在理性泡沫中的确定性泡沫、持续再生性泡沫、内在泡沫,对于外生泡沫的研究缺乏相关的模型,因此对周期性爆炸泡沫的检验尤为必要.采用非线性的MTAR模型对我国沪市周期性爆炸泡沫的存在性进行研究,研究结果显示,1991年1月至1996年12月期间沪市存在泡沫,而1997年1月至2004年12月泡沫成分消失,2005年1月至2009年12月沪市又出现泡沫成分,从而证实我国沪市存在周期性爆炸泡沫.

Asymmetric Price Transmission Analysis of the International Soybean Market

This study analyzed the asymmetric price transmission in the international soybean market, using data from the US (Chicago Futures), European (Rotterdam), Brazilian (Paranaguá), Argentinian (Rosario Futures and Rosario Spot), and Chinese (Spot and Futures) markets. The study looked at the price transmission between these markets over a period of almost 10 years, from September 2009 to May 2019. The Phillips-Perron unit root test was used to determine the order of integration of the time series. The Engle-Granger cointegration test failed to find any evidence of cointegration between the Chinese and Argentinian markets with any others of the international markets. The lack of cointegration was associated with highly government intervened markets. The cointegration and threshold test proposed by Enders and Siklos, succeeded in rejecting the Null hypothesis and finding cointegration among the series after structural breaks had been taken into account. The BDS test for nonlinearity showed that most of the time series were nonlinear, which prompted the investigation to look into nonlinear modelling. To evaluate asymmetric price transmission, the study used the Threshold autoregressive (TAR) model and the momentum threshold model (MTAR). The Argentine and Chinese markets were primarily suspected of exhibiting asymmetric price transmission due to structural government intervention. However, the test results failed to reject the null hypothesis and revealed asymmetric price transmission between these markets and the international market. As expected, the results found no evidence of asymmetric price transmission in the Paranaguá, Rotterdam, and Chicago markets. Hence, it can be concluded that symmetric price transmission is more prevalent in the global soybean market than asymmetric price transmission.

基于门限协整的长短利率关系研究

This paper concentrates on the relationship between the short and the long interest rate by regression and cointegration.It was found that they have same direction to each other,and the spread can explain some variant of the long interest rate.The granger cointegration relationship was not found by Johansen Test,but a threshold cointegration relationship was found between them by Enders-Siklos test.In the end,the paper gives some suggestions for the authority.

欧佩克与非欧佩克原油价格之间的长期动态变化特征——当欧佩克与非欧佩克的价格系列不对称时，欧佩克的价格调整比非欧佩克慢得多

利用ECM-TAR（MTAR）-CGARCH模型对欧佩克（OPEC）与非OPEC原油价格之间的长期动态变化特征进行了研究，结果表明：对于所有生产国，价格冲击将变得更持久以及更动荡，且国际原油价格的动荡性具有长时记忆；由于暂时性差异里的高短期波动，无论是OPEC还是非OPEC油价都没有半衰期定义；OPEC价格调整过程与长期均衡的正偏差相关联意味着OPEC生产商不喜欢温和的油价，而油价过高时非OPEC生产国更倾向于迅迷调整，即它们之间存在准竞争行为以及不同利润和定价策略；除了在有负误差修正项的MTAR模型中，非OPEC不严格遵守OPEC策略。

我国股市投机泡沫分析——基于非线性协调整关系的实证检验

近期研究表明投机泡沫具有周期性破灭特性,但传统检验方法无法针对我国股票市场的特点识别投机泡沫的这种特性,这会对股市泡沫的存在性造成误判。因此,本文引入MTAR模型,通过检验协整残差的非对称调整假设,对我国股票市场发展的不同阶段是否存在泡沫现象进行对比分析。结果表明,长期来看我国股票价格和其内在价值之间存在着均衡关系,但短期内对均衡的调整是非对称的,即存在周期性破灭的投机泡沫,且自2001年下半年以来这种泡沫成分正在逐渐减退。在此基础上进一步揭示了我国股票市场价格波动的深层原因。

基于门限协整的猪粮价格关系研究

本文对生猪价格和玉米价格之间的动态关系进行了研究,发现两者呈正相关关系,玉米价格是生猪价格变化的Granger原因。E-G协整检验表明,生猪价格和玉米价格存在线性协整关系,Enders-Siklos检验表明,两者之间存在有门限的惯性长期均衡关系,猪粮价差减少时的调整速度比猪粮价差增加时的调整速度快。价值规律的作用、政府的不同应对措施和生猪生产过程的特点等是这些现象产生的主要原因。最后,文章提出改进生猪市场价格统一信息平台、普及相关信息到基层猪农和广大消费者,以形成良好的市场预期;在影响肉价及引导猪农决策的时候充分考虑肉价、粮价之间的非对称调整等建议。