涨跌停机制的绩效:上海股市的经验分析

一直以来,理论界和实务界对证券市场实施涨跌停机制的效果存在争议.本文以改进了的Kim和Rhee(1997)的研究方法为基础,结合上海股市的个股价格资料,从波动率溢出假设、延迟价格发现假设和交易干涉假设三个方面对上海股市涨跌停机制的绩效进行实证考察.研究结果表明,中国股市的涨跌停机制是缺乏效率的.文章的最后提出了放宽价格限制幅度和采取不对称的涨跌停机制的政策建议.     

Intradaily volatility and adjustment

Intradaily volatility is related to the speed of adjustment of prices towards their intrinsic values. The decomposition of volatility into intrinsic and noise related components is demonstrated to be impacted by speeds of adjustment. Intradaily speeds of adjustment are estimated for U.K. index data and some empirical evidence of overreaction at the open and underreaction at the close of the trading day found for the FTSE100 index. The major result that we report in this paper is that differential intradaily volatilities at the index level are related to differential speeds of adjustment, thus providing insights into the similar results reported in U.S. index studies, such as [Gerety, M., Mulherin, J., 1994. Price formation on stock exchanges: the evolution of trading within the day. The Review of Financial Studies 7, 609–629].     

ARCH and GARCH models vs. martingale volatility of finance market returns

ARCH and GARCH models assume either i.i.d. or ‘white noise’ as is usual in regression analysis, while also assuming memory in a conditional mean square fluctuation with stationary increments. We will show that ARCH/GARCH is inconsistent with uncorrelated increments, violating the i.i.d. and ‘white’ assumptions, and violating finance data and the efficient market hypothesis as well.     

国际金融市场波动溢出效应与动态相关性

在DCC GARCH、DCC EGARCH、DCC TGARCH方法下,采用中、美、日、德、英等国家1993年1月至2013年12月的金融数据,实证得出如下结论：样本国市场利率和股指波动率呈现尖峰、肥尾、有偏的特征,更为符合t分布。样本国市场利率波动表现出显著的溢出效应、杠杆效应和联动效应。样本国股指波动率对中国股指波动率的溢出效应趋于增强,特别在美国金融危机后。样本国利率波动对中国股指波动率具有一定的溢出效应和杠杆效应,但影响程度非常低。治理世界性金融风险,各国当局应加强政策协调性,合理进行风险分担。     

网络嵌入、集聚模仿与大学衍生企业知识溢出——基于中国三大海洋工程装备制造业集群的实证研究

引入新网络特征——空间集聚结构发现,我国企业集群知识溢出存在空间模仿效应。为此,利用空间计量模型修正社会网络分析结果,考察大学衍生企业网络嵌入演进对企业集群知识溢出的真实影响。结果表明,产业关联、信任、关系联结规模和中介中心度有助于提高企业集群知识溢出水平,知识认同度和互惠程度对知识溢出的影响存在最优均衡;网络嵌入对知识溢出的影响存在明显的空间模仿效应,在连续性知识空间更多表现为邻近效应,在间断性知识空间则表现为异质效应,集群内空间模仿效应强于集群间;在控制空间效应后,仅在波纹状集聚结构的环渤海集群存在结构洞与知识溢出的负向关联。基于上述结果,结合我国国情提出海洋装备集群未来发展政策及启示。     

Modelling international tourism and country risk spillovers for Cyprus and Malta

Small Island Tourism Economies (SITEs) are developing sovereign countries that rely on tourism as a source of exports, and need a consistent inflow of foreign investment in order to facilitate economic growth. Access to international capital markets helps SITEs smooth out their consumption over time, while absorbing adverse domestic production shocks. This paper provides a comparison of tourism growth, country risk returns and their associated volatilities (or uncertainty) for 2 SITEs, namely Cyprus and Malta. Monthly data are available for both international tourist arrivals and composite country risk ratings compiled by the International Country Risk Guide (ICRG) for the period May 1986 to May 2002. The time-varying conditional variances of tourism growth and country risk returns for the 2 SITEs are analysed using multivariate models of conditional volatility. Empirical results show that Cyprus and Malta are complementary destinations for international tourists. Changes to tourism patterns in Cyprus lead to changes to tourism patterns in Malta. Hence, tour operators and national tourism promotion authorities in Cyprus and Malta should collaborate closely in marketing and promoting joint tourism products. Moreover, foreign entities interested in investing in the tourism sectors of Cyprus and Malta should consider investment projects that span a long period of time. The performance of the tourism sector and the associated composite risk are independent of each other for the two countries. However, there is a direct relationship between the tourism sectors of Cyprus and Malta and their respective country risk settings.     

高速铁路对居民消费的空间溢出效应研究

高速铁路开通对居民消费发展具有重要影响。本文基于2003-2017年的省级面板数据,利用空间杜宾模型检验了高速铁路对居民消费的空间溢出效应。结果表明:(1)我国居民消费存在明显的空间集聚特征;(2)周边地区的高铁运营对本地区的居民消费水平有促进作用,但二者并非简单的线性关系,高速铁路对我国居民消费水平的影响呈倒U型;(3)周边地区高铁通过影响当地经济发展水平和旅客周转量来促进当地居民消费水平提升。为此,我国需要充分利用居民消费的空间依赖性来改善各地区居民的消费,完善和优化现有的高铁网络,以高铁发展带动消费水平提升,为经济可持续发展提供适宜的消费环境。     

CEV模型下有交易成本和随机波动率的亚式期权定价问题的文献综述

随着金融衍生品的发展,对其进行定价成为理论和实务操作中的重点。亚式期权作为一种强依赖路径的衍生品,在金融市场中有套期保值作用,在管理中有经理股票期权激励作用。因此,设计出更加切合市场实际的定价模型非常重要。本文选取了相比较B-S模型更加实际的CEV模型作为标底资产的路径过程,加入随机波波动率服从有限Markov链的情况下有交易成本的亚式期权定价公式。在已有的相关文献参考下,可以得出其偏微分方程。并且通过二叉树算法,实现定价计算。     

International trade,risk taking and welfare

This paper shows that the gains from opening up to international trade are smaller when firms do not fully internalize downward risk. I develop a general equilibrium model with two key assumptions. First, when faced with adverse productivity shocks, employers can lay off workers without fully paying the social costs of their layoff decisions, a common feature of many institutions. Second, when opening to international trade, the elasticity of demand perceived by an industry increases. In this setup, I show that international trade induces firms to take more risk and (i) raises the equilibrium unemployment rate, (ii) increases the volatility of sectoral sales and (iii) increases welfare proportionately less than in the absence of the externality. Inducing firms to internalize the costs of layoff (Blanchard and Tirole, 2003) therefore appears even more important in a globalized world.     

How to make Dupire’s local volatility work with jumps

There are several (mathematical) reasons why Dupire’s formula fails in the non-diffusion setting. And yet, in practice, ad-hoc preconditioning of the option data works reasonably well. In this note, we attempt to explain why. In particular, we propose a regularization procedure of the option data so that Dupire’s local vol diffusion process recreates the correct option prices, even in manifest presence of jumps.