Does options trading affect audit pricing?

We examine the impact of options trading on audit pricing for a sample of US firms over the period from 2004 to 2021. We find that options trading is significantly and negatively related to audit fees, indicating that firms characterized by higher options trading incur lower audit fees. Auditors spend a lower number of days auditing firms with higher options trading and firms with higher options trading experience lower probabilities of lawsuits, and misstatements, and lower likelihood of material weaknesses and auditor opinion on internal controls. The impact of options trading on audit fees is stronger when the auditor is located further away from the audited firm, for firms with non‐specialized auditors, higher information asymmetry problems, poorer earnings and lower governance quality. Overall, our findings underscore the significance of options trading in improving a firm's information environment and reducing litigation risk, resulting in lower audit fees

DyGLIP: A Dynamic Graph Model with Link Prediction for Accurate Multi-Camera Multiple Object Tracking

Multi-Camera Multiple Object Tracking (MC-MOT) is a significant computer vision problem due to its emerging applicability in several real-world applications. Despite a large number of existing works, solving the data association problem in any MC-MOT pipeline is arguably one of the most challenging tasks. Developing a robust MC-MOT system, however, is still highly challenging due to many practical issues such as inconsistent lighting conditions, varying object movement patterns, or the trajectory occlusions of the objects between the cameras. To address these problems, this work, therefore, proposes a new Dynamic Graph Model with Link Prediction (DyGLIP) approach to solve the data association task. Compared to existing methods, our new model offers several advantages, including better feature representations and the ability to recover from lost tracks during camera transitions. Moreover, our model works gracefully regardless of the overlapping ratios between the cameras. Experimental results show that we outperform existing MC-MOT algorithms by a large margin on several practical datasets. Notably, our model works favorably on online settings but can be extended to an incremental approach for large-scale datasets.Comment: accepted at CVPR 202

Feasibility of wearable monitors to detect heart rate variability in children with hand, foot and mouth disease

Hand foot and mouth disease (HFMD) is caused by a variety of enteroviruses, and occurs in large outbreaks in which a small proportion of children deteriorate rapidly with cardiopulmonary failure. Determining which children are likely to deteriorate is difficult and health systems may become overloaded during outbreaks as many children require hospitalization for monitoring. Heart rate variability (HRV) may help distinguish those with more severe diseases but requires simple scalable methods to collect ECG data.We carried out a prospective observational study to examine the feasibility of using wearable devices to measure HRV in 142 children admitted with HFMD at a children's hospital in Vietnam. ECG data were collected in all children. HRV indices calculated were lower in those with enterovirus A71 associated HFMD compared to those with other viral pathogens.HRV analysis collected from wearable devices is feasible in a low and middle income country (LMIC) and may help classify disease severity in HFMD

Associations of Underlying Health Conditions With Anxiety and Depression Among Outpatients: Modification Effects of Suspected COVID-19 Symptoms, Health-Related and Preventive Behaviors

Objectives: We explored the association of underlying health conditions (UHC) with depression and anxiety, and examined the modification effects of suspected COVID-19 symptoms (S-COVID-19-S), health-related behaviors (HB), and preventive behaviors (PB).Methods: A cross-sectional study was conducted on 8,291 outpatients aged 18–85 years, in 18 hospitals and health centers across Vietnam from 14th February to May 31, 2020. We collected the data regarding participant's characteristics, UHC, HB, PB, depression, and anxiety.Results: People with UHC had higher odds of depression (OR = 2.11; p < 0.001) and anxiety (OR = 2.86; p < 0.001) than those without UHC. The odds of depression and anxiety were significantly higher for those with UHC and S-COVID-19-S (p < 0.001); and were significantly lower for those had UHC and interacted with “unchanged/more” physical activity (p < 0.001), or “unchanged/more” drinking (p < 0.001 for only anxiety), or “unchanged/healthier” eating (p < 0.001), and high PB score (p < 0.001), as compared to those without UHC and without S-COVID-19-S, “never/stopped/less” physical activity, drinking, “less healthy” eating, and low PB score, respectively.Conclusion: S-COVID-19-S worsen psychological health in patients with UHC. Physical activity, drinking, healthier eating, and high PB score were protective factors

Order submission strategies of institutional and individual investors

This thesis provides three essays on the order submissions of institutional and individual investors in a limit order book market, the Australian Stock Exchange (ASX). In addition, the thesis examines the effect of the removal of broker identifications (IDs) on investors’ order submissions on the ASX. Using the concept of order aggressiveness, which reflects investors’ impatience for trading, the first essay investigates the decision of institutional and individual investors to demand liquidity (submit market orders) and supply it (place limit orders). The findings indicate that the order aggressiveness of institutional and individual investors is positively related to the same-side market depth and negatively related to the opposite-side market depth and the bid-ask spread. Institutional investors are also more aggressive in their order submissions when volatility increases in large capitalization (cap) stocks, whereas both institutional and individual investors are less aggressive when volatility increases in medium (mid) cap stocks. Institutions and individuals follow different order submission patterns throughout the trading day, with institutions being more aggressive early in the trading day and individuals becoming more aggressive as trading progresses. Finally, following the removal of broker IDs on the ASX, both institutional and individual investors become less aggressive and more willing to supply liquidity and display their orders in the central limit order book. The second essay focuses on the information content of the limit order book and examines how it is impacted by the removal of broker IDs. This essay documents a negative relation between future volatility and variations in the liquidity provision in the order book, as captured by the order book slope. This essay also shows that the slope of the limit order book on the demand (buy) side is more informative about future volatility than the slope of the limit order book on the supply (sell) side. Institutional investors’ limit orders are also more informative about future volatility than individual limit orders. Finally, institutional limit orders become more informative about future volatility after the removal of broker IDs on the ASX, whereas minimal impact is observed for the informativeness of individual limit orders. Overall, the results in the first and second essays imply that the removal of broker IDs on the ASX makes investors more willing to submit and expose their informative limit orders in the limit order book. Therefore, this thesis supports the ASX’s decision to stop disclosing broker identity information in the central limit order book. The third essay examines the volume-volatility relation and the roles of the number of trades and average trade size, institutional trading and individual trading, and order imbalance in the volume-volatility relation. This essay provides evidence supporting a positive relation between trading volume and volatility. In addition, the number of trades has a more significant effect on volatility than average trade size. When the number of trades is decomposed into the number of trades of different sizes, the number of trades in the medium size category often has the most significant impact on volatility. This essay also shows that institutional trading and individual trading are positively related to volatility and individual trading often has a more significant effect on volatility than institutional trading. Finally, the findings in this essay indicate that on the ASX, a limit order book market, order imbalance is not the main factor behind the volume-volatility relation

Order submission strategies of institutional and individual investors

This thesis provides three essays on the order submissions of institutional and individual investors in a limit order book market, the Australian Stock Exchange (ASX). In addition, the thesis examines the effect of the removal of broker identifications (IDs) on investors’ order submissions on the ASX. Using the concept of order aggressiveness, which reflects investors’ impatience for trading, the first essay investigates the decision of institutional and individual investors to demand liquidity (submit market orders) and supply it (place limit orders). The findings indicate that the order aggressiveness of institutional and individual investors is positively related to the same-side market depth and negatively related to the opposite-side market depth and the bid-ask spread. Institutional investors are also more aggressive in their order submissions when volatility increases in large capitalization (cap) stocks, whereas both institutional and individual investors are less aggressive when volatility increases in medium (mid) cap stocks. Institutions and individuals follow different order submission patterns throughout the trading day, with institutions being more aggressive early in the trading day and individuals becoming more aggressive as trading progresses. Finally, following the removal of broker IDs on the ASX, both institutional and individual investors become less aggressive and more willing to supply liquidity and display their orders in the central limit order book. The second essay focuses on the information content of the limit order book and examines how it is impacted by the removal of broker IDs. This essay documents a negative relation between future volatility and variations in the liquidity provision in the order book, as captured by the order book slope. This essay also shows that the slope of the limit order book on the demand (buy) side is more informative about future volatility than the slope of the limit order book on the supply (sell) side. Institutional investors’ limit orders are also more informative about future volatility than individual limit orders. Finally, institutional limit orders become more informative about future volatility after the removal of broker IDs on the ASX, whereas minimal impact is observed for the informativeness of individual limit orders. Overall, the results in the first and second essays imply that the removal of broker IDs on the ASX makes investors more willing to submit and expose their informative limit orders in the limit order book. Therefore, this thesis supports the ASX’s decision to stop disclosing broker identity information in the central limit order book. The third essay examines the volume-volatility relation and the roles of the number of trades and average trade size, institutional trading and individual trading, and order imbalance in the volume-volatility relation. This essay provides evidence supporting a positive relation between trading volume and volatility. In addition, the number of trades has a more significant effect on volatility than average trade size. When the number of trades is decomposed into the number of trades of different sizes, the number of trades in the medium size category often has the most significant impact on volatility. This essay also shows that institutional trading and individual trading are positively related to volatility and individual trading often has a more significant effect on volatility than institutional trading. Finally, the findings in this essay indicate that on the ASX, a limit order book market, order imbalance is not the main factor behind the volume-volatility relation

Anonymity and order submissions

We investigate the effect of the removal of broker identities on institutional and individual order submissions on the Australian Stock Exchange (ASX). We document declines in order aggressiveness and effective spreads for both institutional and individual investors after the switch to the anonymous trading system. Institutions are more willing to improve the best quotes than individuals, especially in the anonymous market. Anonymity also reduces the “picked off” risk for individual limit orders. Overall, our findings highlight the benefits of withholding brokers' IDs in the form of lower transaction costs and higher liquidity supply and thus support the ASX's decision to stop disclosing broker identity information.