#br# 融资融券加大了沪深股市波动吗*

融资融券设计初衷是通过融资加强市场流动性和通过融券提供投资者规避价格下跌风险的金融工具，改善由供求关系严重失衡导致市场巨幅震荡的局面，实现资本市场长期稳定的目标。实际操作中，融资融券疏通货币市场和资本市场间的资金流动，撬动巨额资金涌入股市；融资规模扩张过快而融券做空力量薄弱，业务结构发展严重失衡，导致两融业务具有“小冲击、大波动”的金融加速效应，放大了外部冲击引起股价上涨和下跌的幅度。协整回归分析表明，两融业务规模的扩张和收缩对上证指数涨跌具有显著的同向影响。TGARCH事件模型结果进一步证实融资融券从稳定股价到加剧波动的功能变化。随着标的股票扩容和业务常规化，两融业务导致股市投机过度，加剧了沪深两市的资产价格异动，没有达到平抑波动的设计预期。     

A NEW LOOK AT SHORT‐TERM IMPLIED VOLATILITY IN ASSET PRICE MODELS WITH JUMPS

We analyze the behavior of the implied volatility smile for options close to expiry in the exponential Lévy class of asset price models with jumps. We introduce a new renormalization of the strike variable with the property that the implied volatility converges to a nonconstant limiting shape, which is a function of both the diffusion component of the process and the jump activity (Blumenthal–Getoor) index of the jump component. Our limiting implied volatility formula relates the jump activity of the underlying asset price process to the short‐end of the implied volatility surface and sheds new light on the difference between finite and infinite variation jumps from the viewpoint of option prices: in the latter, the wings of the limiting smile are determined by the jump activity indices of the positive and negative jumps, whereas in the former, the wings have a constant model‐independent slope. This result gives a theoretical justification for the preference of the infinite variation Lévy models over the finite variation ones in the calibration based on short‐maturity option prices.     

The Informational Role of Short Sellers: The Evidence from Short Sellers’ Reports on US‐Listed Chinese Firms

Using US‐listed Chinese firms as the setting, this paper studies a novel channel through which investors can acquire information about firms’ financial reporting quality, that is, the reports published voluntarily by short sellers. I find that short sellers tend to target firms that have financial reporting red flags and that exhibit ‘good’ operating performance and stock valuations. Targeted firms experience an average three‐day cumulative abnormal return (CAR) of ?6.4%, and ?13.6% for initial coverage of the firm, and the CARs are more negative when the reports allege more severe misconduct of the firms. Non‐targeted firms also experience losses in value following short seller reports, especially when they hire the same non‐Big 4 auditors as targeted firms and when their earnings quality is poor. In comparison, analysts fail to perform proper due diligence and are much less effective than short sellers in exposing misreporting risk in Chinese firms.     

Myopic market pricing and managerial myopia

This paper develops a firm‐level measure of myopic market pricing, which captures the extent to which the market overvalues short‐term expected abnormal earnings relative to longer‐term ones. The empirical analysis shows that myopically priced firms manage earnings more actively and invest less in R&D. The impact of myopic market pricing is concentrated in firms where managers cater more to market pricing, that is, in firms with greater short‐term investor ownership, with CEO compensation that is more sensitive to the firm share price, and with higher equity dependence. Additional tests show that these findings are robust to the consideration of market (under)overpricing. The results suggest that when managers cater to market pricing, market myopia encourages managerial myopia.     

福建省公路网可达性研究

基于福建省区域系统的开放性,以县域为研究单元,采用平均旅行时间指标,利用TransCAD软件对福建省公路网的可达性进行计算,并分析可达性空间格局的特征。     

手机二维码在高校数字化图书馆中的应用

文章提出结合移动通信技术和图书馆自动化技术,通过短信服务、WEB／WAP网络将手机二维码和图书馆自动化系统有效的整合在一起,构建新型高校数字化图书馆的模型、论述了手机二维码在高校数字化图书馆的各项管理和服务流程中的应用,对未来通过结合图书馆自动化系统、短信服务和手机二维码构建高校数字化图书馆子以展望。     

卖出套期保值适用范围分析

如果交易者未来有买入或卖出现货商品的需求,但担心价格趋势对自己不利,则可通过在期货市场建立套期保值头寸的方式,将未来交易现货的价格锁定在目前较为满意的价格水平上,达到规避现货价格风险的目的。文章认为,采用套期保值策略规避现货价格风险具有严格的原则和依据,但目前部分教材和分析师撰写的研究报告,关于卖出套期保值策略适用情况的介绍存在一定的问题,可能造成参与者的错误决策,文章提出以上问题并进行分析探讨,以使参与者正确理解和选择套期保值策略。     

小学语文长文短教之我见

"题目"是文章的眼睛,透过文题可以窥探文章的主旨。通过"题目",教师可以熟练地驾驭教材,有效地组织课堂教学,找到教学的突破口,把握文章的中心思想。     

SHORT‐RUN POLICY COMMITMENT WHEN INVESTMENT TIMING IS ENDOGENOUS: ‘MORE HARM THAN GOOD?’

In our model, firms choose when to set cost‐reducing investment and the government, which only has short‐run commitment power, sets an output subsidy. We show that firms that delay investment without government intervention have an incentive to invest early under policy activism, strategically underinvesting or overinvesting to obtain larger subsidies. The policy scheme thus creates a new, potentially more harmful, distortion. Under oligopoly, a firm has a weaker incentive to manipulate policy than under monopoly, which makes policy intervention less harmful. We investigate when the government may do better by adhering to laissez‐faire than by engaging in active policy intervention.     

Single Stock Futures as a Substitute for Short Sales: Evidence from Microstructure Data

Abstract:  We examine how the introduction of single-stock futures impacts short sale costs and short interest levels in the underlying spot market. We find that short selling in the underling securities declines, after futures are introduced, the cost of borrowing stock for short sales declines and the available unborrowed supply of lendable shares increases. These results are consistent with futures exchanges providing a low-cost substitute market for establishing short positions. Microstructure evidence also suggests that the lower cost and greater ease of short selling via futures markets draws informed traders from the spot market.