Forecasting stock volatility with economic policy uncertainty: A smooth transition GARCH-MIDAS model

Given that policy uncertainty shocks in the economic environment can exacerbate financial market volatility and pose financial risks, this paper utilizes a smooth transition version of the GARCH-MIDAS model to investigate the impact of different structural state changes in economic policy uncertainty (EPU) on stock market volatility. The extended model explains the nonlinear effects of the macro variables and the structural break changes in regime transitions. The empirical results confirm that the EPU indicators provide effective prediction information for stock volatility from the in-sample and out-of-sample analyses, which reveals that the smooth transition model provides an effective method for detecting the possible regime changes between stock volatility and macroeconomic uncertainty. Additionally, we further confirm that some category-specific EPU indicators also have strong smooth transition behaviour with respect to stock volatility. More important, our new model provides significant economic value to investors from a utility gain perspective. Overall, the institutional changes present in EPU play a nonnegligible and important role in stock market volatility. Accurate identification of the structural features of financial data helps investors deepen their understanding of the sources of stock market volatility.     

Gauging the effects of stock liquidity on earnings management: Evidence from the SEC tick size pilot test

This paper studies whether stock market liquidity has a causal effect on real earnings management. We introduce a new and cleaner identification of liquidity shock - the 2016 Tick Size Pilot Program - to show that firms with less liquid stocks are more likely to engage in real earnings management. We provide direct evidence that stock liquidity helps to deter real earnings management via enhancing governance by long-term institutional investors through trading and direct intervention, and via facilitating short selling to discipline managers. The effect is stronger in firms that do not pay dividends.     

中国式卖空机制与高管减持——基于融资融券分步扩容的准自然实验

本文以我国的融资融券制度为背景,结合双重差分模型,研究卖空机制对上市公司高管减持行为的影响。研究发现,相对于非融券标的,可融券标的公司高管的月减持比例在允许卖空后下降22%,这种抑制作用在小规模、高盈余平滑度以及非国有公司中体现得更为明显。其次,成为可融券标的后,股价定价效率提高,高管减持收益显著下降。进一步地,本文将高管的减持行为分为定期性与投机性两类,发现卖空机制显著抑制了高管基于信息优势和股价偏差的投机性减持行为。     

Does common ownership constrain managerial rent extraction? Evidence from insider trading profitability

This study identifies a new economic benefit of common institutional ownership, which refers to the increasingly contentious phenomenon of U.S. firms sharing stockholders with their industry competitors. We find a significantly negative relation between common ownership and insider trading profitability. The disciplinary effect of common ownership on opportunistic insider trading is particularly evident when the information effects of common ownership are greater, when common owners are more likely to benefit from positive governance externalities, and in the subset of trades made by opportunistic insiders. Using the exogenous variations in common ownership induced by financial institution mergers, we conduct a difference-in-differences analysis and find consistent results. We also provide evidence that common owners encourage firms to impose ex-ante restrictions on insider trading and take ex-post actions to discipline opportunistic insiders by voting against management. Overall, our findings suggest that common institutional shareholders have information advantages, governance incentives, and effective means to constrain opportunistic insider trading.     

Economic policy uncertainty and momentum

We show that a news‐based measure of economic policy uncertainty (EPU) negatively forecasts momentum. A 1‐standard‐deviation increase in EPU is associated with a 1.11% decrease in risk‐adjusted momentum returns. The predictive power of EPU is robust after controlling for previously documented economic state variables and macroeconomic uncertainty. We provide an explanation for these results from the perspective of a fund flow‐induced trading mechanism and offer direct empirical support. The literature documents that momentum can be partially attributed to performance‐chasing mutual fund flows. We find that this flow‐induced mechanism functions more effectively in low EPU states, thereby generating stronger stock momentum.     

股票价格、货币政策和宏观经济波动

本文对包含股票价格在内的新凯恩斯模型的结构方程进行估计,分析了股票价格和货币政策与宏观经济波动之间的关系,认为股票价格与宏观经济波动密切相连,货币政策调整可以平滑经济波动。在此基础上,比较了不同的货币政策规则的宏观调控效果,得到的结论是,将股票价格波动纳入货币政策的调控范围会改善货币政策效果,有助于稳定宏观经济。     

Does stronger corporate governance constrain insider trading? Asymmetric evidence from Australia

We investigate the role of internal corporate governance in limiting opportunities for ASX company ‘insiders’ to extract abnormal returns from trading ‘own shares’. We show that stronger governance translates into more restrictive insider trading policies and, while not resulting in lower insider purchase volumes, values or profits, it does reduce insider selling profitability. Firm size and increasing trading policy restrictiveness is associated with reduced insider purchase profitability while insider sale profitability is reduced by aggregate governance, trading restrictions and increasing trading policy restrictiveness. We conclude that internal firm governance constrains insider sales but not purchases, providing contrarian trading signals.     

上市公司大股东的“掏空”路径及制衡机制研究

在中国股权相对集中或高度集中的上市公司中,由于控股股东或大股东掌握着公司的实际控制权,大股东的自利天性与机会主义行为可能导致其利用资金占用、关联交易、股利政策和内幕交易等种种手段实现大股东掏空。为遏制大股东掏空现象的泛滥,需从内部治理和外部制衡两个角度,构建大股东掏空的内外部制衡机制,以保护中小股东权益的不受侵害。     

What can we learn about the market reaction to macroeconomic surprise? Evidence from the COVID-19 crisis

We investigate the impact of macroeconomic surprise and uncertainty on G7 financial markets around COVID-19 pandemic using two real-time, real-activity indexes recently constructed by Scotti (2016). We applies the wavelet analysis to detect the response of the stock markets to the macroeconomic surprise and an uncertainty indexes and then we use NARDL model to examine the asymmetric effect of the news surprise and uncertainty on the equity markets. We conduct our empirical analysis with the daily data from January, 2014 to September, 2020. Our findings indicate that G7 stock markets are sensitive to the macroeconomic surprise and uncertainty and the effect is more pronounced at the long term than the short term. Moreover, we show that the COVID-19 crisis supports the relationship between the macroeconomic indexes and the stock prices. The results are useful for investment decision-making for the investors on the G7 stock indices at different investment horizons.     

Insider-trading,discretionary accruals and information asymmetry

Using US data for the period from 2004 to 2012 and alternative discretionary accruals measures, we examine whether insiders manipulate earnings in an asymmetric information environment to profit from their informed trades, and whether the intervening information environment influences the relationship between earnings management and insider trading. We show that insider trading dominated by sell trades has a positive association with discretionary accruals. The incremental effect of information asymmetry as well as the interaction with insider trading is also prevalent in this relation, confirming the moderating effect of asymmetric information. Further, we show that the active involvement of some key insiders in high discretionary accruals is for personal benefit more in growth firms than in value firms. Our results also suggest that earnings management allows for insiders’ opportunistic, rather than routine, buy and sell trades. Our findings highlight that regulators should oversee and scrutinise both insider trading and earnings management to mitigate the risk of the opportunistic behaviour of insiders to avoid future corporate scandals.     

MACROECONOMIC NEWS,STOCK TURNOVER,AND VOLATILITY CLUSTERING IN DAILY STOCK RETURNS

We study volatility clustering in daily stock returns at both the index and firm levels from 1985 to 2000. We find that the relation between today's index return shock and the next period's volatility decreases when important macroeconomic news is released today and increases with the shock in today's stock market turnover. Collectively, our results suggest that volatility clustering tends to be stronger when there is more uncertainty and disperse beliefs about the market's information signal. Our findings also contribute to a better understanding of the joint dynamics of stock returns and trading volume.     

卖空机制能够约束内部人减持吗？——基于融资融券制度的经验证据

本文以我国放松卖空管制为视角,探究其对内部人减持的影响。研究表明,卖空机制能够抑制企业内部人减持行为。机制分析发现,卖空对内部人减持的抑制作用是通过缓解股权高溢价实现的。进一步研究表明,卖空能够抑制大股东、董事以及管理层减持,但对监事减持无影响;卖空能够降低内部人减持的获利程度,并且在内部人减持动机更大时,对内部人减持的抑制作用更强;卖空通过约束内部人减持提升了股票定价效率,还有助于降低内部人增持行为。本文的研究结论丰富了卖空和内部人减持领域的文献,并对政府部门完善制度设计具有启示意义。     

Management friendship and insider opportunism

This study documents a significant increase in both trading activity and profitability of opportunistic top managers when a CEO develops a strong connection with subordinate executives through co-opting the executives who share social ties with him/her. This baseline evidence is robust to endogeneity concerns, alternative measures of management connection and insider opportunism, as well as controlling for other CEO and board attributes. Further analyses reveal that interpersonal connections between top managers are more likely to increase opportunistic insider trading in firms with lower-quality voluntary disclosures, more sociable executives, and relaxing legal barriers to insider trades. Increased insider opportunism in response to the CEO’s connection with other top executives engenders less informative stock prices and depresses stock market liquidity. Finally, insider trades in firms with stronger management connection are more predictive of future stock returns.     

内部控制与异质机构持股的治理效应

本文实证检验了不同内部控制水平下,异质机构持股在抑制管理层盈余操纵方面的公司治理效应。研究发现,相比外地或短期机构持股,本地或长期机构持股更有助于提升应计质量和降低盈余噪音;当公司存在实质性内部控制缺陷时,本地或长期机构持股在抑制管理层盈余操纵方面的治理效应显著降低;相比国有控股,异质机构持股治理效应的发挥在非国有控股公司中受内部控制的影响更大;当公司存在财务报告实质性内控缺陷时,异质机构持股发挥的治理效应明显更弱。这些结果表明,异质机构持股治理效应的发挥离不开公司内部控制机制,二者之间是互补而非替代关系,这种互补关系主要由财务报告内部控制缺陷驱动。本研究有助于深化理解异质机构持股影响公司治理的具体作用机理,为实务界和监管机构改善公司治理、加强投资者保护提供经验参考。     

Stock liquidity and managerial short-termism

We examine whether stock liquidity exacerbates or mitigates managerial short-termism. Utilizing earnings management as a proxy for managerial short-termism, we establish three major findings. First, firms with liquid stocks engage in less accrual-based and real earnings management. Second, the effect of stock liquidity on earnings management is amplified for firms with high levels of managerial pay-for-performance sensitivity. Third, the positive association between the intensity of earnings management and firm cost of capital is evident only for firms with low stock liquidity. Our findings are consistent with the threat of blockholder exit as the main governance channel through which stock liquidity discourages opportunistic earnings management and mitigates managerial short-termism.     

A study of firms surrounding the threshold of Sarbanes–Oxley Section 404 Compliance

This study examines whether firms surrounding the Sarbanes–Oxley Section 404 market value compliance threshold behave opportunistically to reduce their market value to avoid compliance with Section 404. We find evidence that those firms reduce their market value temporarily during threshold measurement quarters, whereas control firms experience increasing market value. We find strong evidence of dampened stock returns and some evidence of insider trading as means to reduce the float. Additionally, we find that downward earnings management is used as a mechanism to alter investors’ expectations of firm value in order to temporarily reduce stock prices. We consider this opportunistic evidence of regulatory avoidance. Finally, we find that the likelihood of avoidance increases with the power of the CEO and decreases with the strength of the monitoring of the CEO, which suggest that avoidance is more likely to happen in firms with poor corporate governance mechanisms.     

Effects of investor sentiment and country governance on unexpected conditional volatility during the COVID-19 pandemic: Evidence from global stock markets

This paper first investigates the relationship between investor sentiment, captured by internet search behaviour, and the unexpected component of stock market volatility during the COVID-19 pandemic. According to data on 12 major stock markets, our research indicates a positive correlation between the Google search volume index on COVID-19 and the unexpected volatility of stock markets. The result suggests that greater COVID-19-related investor sentiment during this pandemic is associated with higher stock market uncertainty.Our study further examines whether country-level governance plays a role in protecting stock markets during this pandemic and reveals that the unexpected conditional volatility is lower when a country's governance is more effective. The impact of investor sentiment and country governance on unexpected volatility after the initial shock of COVID-19 is also investigated. The findings demonstrate the importance of establishing good country-level governance that can effectively reduce stock market uncertainty in the context of this pandemic, and support continual policy development related to investor protection.     

Impact of financial market uncertainty and macroeconomic factors on stock–bond correlation in emerging markets

This paper examines the impact of global financial market uncertainty and domestic macroeconomic factors on stock–bond correlation in emerging markets. In particular, by applying the wavelet analysis approach, we are able to examine stock–bond correlations over different time horizons in ten emerging markets. We find that stock–bond correlation patterns vary significantly between the time horizons. In particular, the correlation in short horizon changes the sign rapidly showing sustainable negative episodes while the correlation in long horizon stays positive most of the time. The most important factor influencing stock–bond correlation in short horizon is the monetary policy stance, while the factors with the greatest long-term impact are inflation and stock market uncertainty. Finally, global stock market uncertainty plays a more significant role than global bond market uncertainty in explaining stock–bond correlations in emerging markets.     

信息不确定、坏消息与投资者交易行为

本文以2000年至2010年的A股上市公司违法违规事件为样本,分析该类事件中信息不确定性的影响,以及市场反应中的投资者交易行为。研究发现:上市公司市场价值在事件日呈显著下跌;然而,与直觉有些相悖的是,信息不确定程度与超额累积收益呈显著正相关,这意味着在坏消息到来时,不确定性反而提高了股票的市场价值;最后,通过对各类投资者在此类事件中的净买入情况分析,我们发现不同投资者的交易行为有明显差异。机构投资者在坏消息中采用了反向交易策略,并且知情交易促进机构投资者的买入。     

卖空者与内幕交易——来自中国证券市场的证据

本文研究上市公司内部人减持、年报、诉讼、分析师评级、停复牌以及高送转等重大公告前后卖空交易行为的变化,系统考察卖空者是否参与内幕交易以及何种因素影响卖空者参与内幕交易,发现卖空率较高的股票具有较低的未来收益,表明卖空者拥有信息优势,属知情交易者;卖空者拥有非常精确的择时交易能力,在重大利空公告前显著增加卖空量,而在利好公告前则显著减少卖空头寸,表明卖空者作为知情交易者的信息优势源自内幕消息;公司内、外部投资者的信息不对称程度越低或公司所在地的法治水平越高,卖空者参与内幕交易的行为就越少。因此,监管机构应密切关注公司重大消息发布前后卖空量的异常变动,同时,完善信息披露规则、健全证券分析师制度并强化法律法规的执行力度,才能有效防范卖空者参与内幕交易。