How did COVID-19 impact air transportation? A first peek through the lens of complex networks

The current outbreak of COVID-19 is an unprecedented event in air transportation. This is probably the first time that global aviation contributed to the planet-wide spread of a pandemic, with casualties in over two hundred countries. As of August 23rd, 2020, the number of infected cases has topped 23 million, reportedly relating to more than 800,000 deaths worldwide. However, there is also a second side of the pandemic: it has led to an unmatched singularity in the global air transportation system. In what could be considered a highly uncoordinated, almost chaotic manner, countries have closed their borders, and people are reluctant/unable to travel due to country-specific lock-down measures. Accordingly, aviation is one of the industries that has been suffering most due to the consequences of the pandemic outbreak, despite probably being one of its largest initial drivers. In this study, we investigate the impact of COVID-19 on global air transportation at different scales, ranging from worldwide airport networks where airports are nodes and links between airports exist when direct flights exist, to international country networks where countries are contracted as nodes, and to domestic airport networks for representative countries/regions. We focus on the spatial-temporal evolutionary dynamics of COVID-19 in air transportation networks. Our study provides a comprehensive empirical analysis on the impact of the COVID-19 pandemic on aviation from a complex system perspective using network science tools.     

The pricing of European airbnb listings during the pandemic: A difference-in-differences approach employing COVID-19 response strategies as a continuous treatment

The COVID-19 pandemic has been a major shock to the global tourism industry. Given its peculiarity, this paper analyzes one of the most intriguing questions in the Airbnb literature – the pricing of Airbnb listings – by taking advantage of a difference-in-differences methodology that largely draws on variations in country-level policy responses to the pandemic. Relying on a dataset containing weekly information from 130,999 continuously active listings across 27 European countries from 2019 to 2020, this study first investigates the exogenous impact of response policies (proxied by the COVID-19 Stringency Index) on demand. Secondly, accounting for the endogeneity of both demand and prices, this research analyzes pricing responses to demand variations. Results show that: i) increases in the COVID-19 Stringency Index cause significant declines in Airbnb demand; ii) increases in demand cause, on average, increases in Airbnb prices; and iii) pricing strategies between commercial and private hosts differ substantially.     

重大疫情下高校辅导员开展思想政治工作的五个着力点

新型冠状病毒感染的肺炎疫情防控过程中,高校大学生是一个不容被忽视的群体。抗疫是近期大学生思想政治教育工作的重中之重,事关大学生身心健康成长的根本利益,事关立德树人教育根本任务的实现。     

Modeling the lockdown relaxation protocols of the Philippine government in response to the COVID-19 pandemic: An intuitionistic fuzzy DEMATEL analysis

The COVID-19 pandemic, which started at Wuhan, has shut down world economies, prompting governments to impose drastic lockdown measures of the economy and the society. As these measures are exhausted, non-COVID-19 related issues such as those associated with the mental and physical well-being of people under lockdowns became an emerging concern. As these issues are evident, not to mention the economic downturn, governments are currently looking at designing lockdown relaxation efforts by simultaneously considering both public health and economic restart. Without documented experiences to rely on, governments are resorting to trial-and-error approach in creating a lockdown exit strategy while preventing succeeding waves of cases that may overwhelm healthcare facilities. Thus, this work pioneers the use of the decision-making trial and evaluation laboratory (DEMATEL) method with intuitionistic fuzzy (IF) sets along with the domain of public health and the emerging COVID-19 pandemic. The DEMATEL handles the intertwined causal relationships among guideline protocols for the relaxation strategy. The intuitionistic fuzzy set theory addresses the vagueness and uncertainty of human judgments in the context of the DEMATEL. A case study of the Philippine government response for the lockdown exit is presented to evaluate the applicability of the proposed method. Findings reveal that compliance of minimum public health standards, limited movement of persons, suspension of physical classes, the prohibition of mass gatherings, non-operation of category IV industries, and non-operation of hotels or similar establishments are the most crucial protocols for such strategy. These findings offer practical insights for the government to allocate resources and impose measures to ensure their implementation, as well as for developing mitigation efforts to cushion their socio-economic impacts. Policy insights and avenues for future works are also discussed.     

Exogenous shocks and managerial preparedness: A study of U.S. airlines’ environmental scanning before the onset of the COVID-19 pandemic

Managerial preparedness is a constant concern for firm stakeholders. This concern is exacerbated during times of immense stress brought about by exogenous shocks. In this paper, we analyze the preparedness of U.S. commercial airline management teams to the largest systematic exogenous shock to date, namely the COVID-19 pandemic in 2019 and 2020. We do this by underpinning the paper with theory on environmental scanning and managerial dysfunction and then documenting the signals and actions of management around multiple public health scares. These include the SARS outbreak, the Swine Flu outbreak and the COVID-19 outbreak. Our results, based off of corporate filings with the SEC, is that airline management had multiple “dry runs” before the COVID-19 outbreak that should have lead them to prepare for financially catastrophic scenarios such as the one observed in 2020. Instead, management teams failed to learn from these, and other, prior shocks. Instead, they focused on other, less serious threats while diffusing their financial buffers through dividends and share buybacks.     

World equity markets and COVID-19: Immediate response and recovery prospects

Following the spread of the COVID-19 pandemic, most global equity market indices experienced significant falls. Recognizing the severe economic impacts of the pandemic, starting from mid-March, many governments announced unprecedented economic rescue packages, which appear to restore investors’ confidence, given the recoveries recorded in most stock markets. However, the recovery performance significantly varies across countries. This paper provides an empirical analysis on what may explain this variation in the recovery performance observed in equity markets across countries. We find that among different types, fiscal stimulus supports seem to be strongly and positively associated with higher recovery that may justify more targeted fiscal supports for the real sector firms to restore investors’ confidence. We also find that the severity of the outbreak, reliance more on natural resource and tourism revenues are negatively associated with countries’ stock market recovery performance.     

财政应对突发公共卫生事件的制度逻辑及其机制完善

财政作为国家治理的基础和重要支柱,在应对新冠肺炎疫情中起着至关重要的作用。将财政应对突发公共卫生的实践内嵌于财政改革发展逻辑框架下进行考察,在对比SARS相关情况的基础上,分析财政应对新冠肺炎疫情的机制,并判断疫情对财政收支的直接影响和间接影响、短期影响和中长期影响。在此基础上,剖析财政应对突发公共卫生事件存在的问题,进而提出加大支持力度、压缩一般性支出、强化资金监管、加强信息交流和公开等近期应急性财税对策,以及健全筹资体制、优化事权划分、调整支出结构、加强绩效管理等中长期制度性财税措施。     

On measuring synchronization of bulls and bears: The case of East Asia

This paper implements estimation and testing procedures for comovements of stock market “cycles” or “phases” in Asia. We extend the Harding and Pagan [Harding, D., Pagan, A.P., 2006. Synchronization of cycles. Journal of Econometrics 132 (1), 59–79] test for strong multivariate nonsynchronization (SMNS) between business cycles to a test that allows for an imperfect degree of multivariate synchronization between stock market cycles. Moreover, we propose a test for endogenously determining structural change in the bivariate and multivariate synchronization indices. Upon applying the technique to five Asian stock markets we find a significant increase in the cross country comovements of Asian bullish and bearish periods in 1997. A power study of the stability test suggests that the detected increase in comovement is more of a sudden nature (i.e. contagion or “Asian Flu”) instead of gradual (i.e. financial integration). It is furthermore argued that stock market cycles and their propensity toward (increased) synchronization contain useful information for both investors, policy makers and financial regulators.     

Information,sell-side research,and market making

The interaction between an investment bank's research and market making arms may have important implications for the trading of a firm's stock. We investigate the impact that research has on the liquidity provided by the bank's market maker. Utilizing a large sample of Nasdaq firms, we show that market makers whose banks also provide research coverage provide more liquidity and contribute more to price discovery than do market makers without such research coverage. Finally, we show that such “affiliated” market makers are less affected by uncertainty following earnings announcements. Our results provide new evidence on the sources of liquidity improvements for Nasdaq firms, and suggest that the information produced by banks in the sell-side research process is beneficial to their market makers.     

新冠肺炎疫情对消费者信心的冲击效果与作用机制 ——基于中国35个城市居民问卷调查的分析

本文基于2018—2020年“中国城市生活质量调查”数据,以新冠肺炎疫情为一次准自然实验,利用双重差分法,检验新冠肺炎疫情对消费者信心的影响。研究发现：新冠肺炎疫情在一定程度上降低了消费者信心,但收入较高人群的消费者信心非但没有降低,反而升高了。另外,从政府信息公开角度进行机制检验发现,政府关于新冠肺炎疫情方面的信息公开会在一定程度上缓解疫情对消费者信心的负面影响。因此,应当理性地看待新冠肺炎疫情对消费者信心的影响,针对特定群体制定相应的政策措施;同时,充分利用各种信息公开渠道,缓解疫情对消费者信心的负面影响,提振消费者信心,激发市场活力。