An Exploratory analysis of flight delay propagation in China

Delay propagation is the flight departure delay caused by the arrival delay of pre-segment flight. Chinese airline market has suffered very poor on-time performance (OTP) in recent years. It is, however, unclear whether delay propagation prevails as one major source for such problem. This study first aims to empirically quantify delay propagation in the Chinese airline market. Specifically, we shed light on heterogenous levels of delay propagations across different airports and airlines. Then, the distinct delay propagation patterns in China are also discussed and compared with other developed airline markets (e.g., the US and Europe). Our estimation is based on OTP data for over 12 million Chinese flights covering the 2015–2017 period. Specifically, it is found that 10 min arrival delay of pre-segment flight within 1 hr before the departure lead to an average of 7.49 mins delay propagation for subsequent departure flight. Arrival delay of earlier pre-segments (1–2 and 2–3 hr before the departure) leads to much less delay propagation, due to longer ground buffer. Chinese airlines arrange longer ground and flight buffer than that of the US airlines to prevent the delay propagation from accumulating along the subsequent flights in a day. Thus, unlike the US market, delay propagation is not the major reason for poor OTP in China. In addition, delay propagation is less prevailing at the Chinese hub airport. This is because China has relied on point-to-point network, which does not require sophisticated schedule coordination. And the local passengers at these Chinese hub airports have higher time value such that the Chinese airlines also try to improve OTP at these hub airports to better serve these lucrative but time-sensitive local passengers. Unlike the European LCCs, Spring Airlines, the largest low-cost carrier (LCC) in China, outperforms major full-service carriers (FSCs) in controlling delay propagation. This finding may also apply to other Northeast Asian LCCs sharing common operational characteristics as Spring Airlines. Last, we find that airlines purposely tolerate moderate departure delays of up to 15 min, which is the threshold that defines delays, no matter whether the pre-segment flight arrives late or on-time. The relevant policy and managerial implications are also discussed.     

The mechanism of credit risk contagion among internet P2P lending platforms based on a SEIR model with time-lag

The credit risk contagion of Internet peer-to-peer (P2P) lending platforms is an important part of Internet financial risk management and supervision. This study analyzes the contagion path of credit risk in Internet P2P lending. Based on complex network theory and the theory of infectious disease dynamics, the characteristics of Internet P2P lending development are combined to construct a SEIR model of credit risk transmission among Internet P2P lending platforms with time lag, and the robustness of the model is analyzed and proven. The influence of platform correlations, the susceptible immune rate, the platform elimination rate, contagion latency, the saturation coefficient, and the susceptibility input rate on credit risk contagion behavior among Internet P2P lending platforms is analyzed, using the equilibrium point and threshold value. The impact of each variable is analyzed by simulation. Corresponding countermeasures and suggestions are proposed to prevent and control credit risk contagion among these platforms.     

黑龙江森工林区林业产业结构演变趋势及优势产业选择

采用灰色预测方法对黑龙江森工林区2018—2027年林业三次产业产值进行预测,并在此基础上利用动态偏离-份额分析方法对此阶段黑龙江森工林区的林业优势产业进行选择。结果表明:2019年黑龙江森工林区林业产业结构将演变为"三、一、二"模式;林业第一产业中的林木育种和育苗、经济林产品的种植和采集业可作为优势产业进行重点发展和管理。因此,提出优化黑龙江森工林区林业产业结构的相关建议:继续巩固发展林木育种和育苗、经济林产品的种植和采集这两个优势产业;推动加工制造业向深加工、精加工的方向转变;加强林业旅游与休闲服务业的竞争力。     

Real-time co-creation and nowness service: lessons from tourism and hospitality

Brands take advantage of technology, social media and constant connectivity to foster organic consumer engagement and interactions towards co-creating personalised customer service. Real-time service offers dynamic engagement with connected consumers. Brands in tourism and hospitality use technology to dynamically enhance consumer experience through co-creation. The integration of real-time consumer intelligence, dynamic big data mining, artificial intelligence, and contextualisation can transform service co-creation by mobilising recourses in the ecosystem. Nowness service emerges by dynamically engaging consumers in experience cocreation in real time. It has five interconnected characteristics that revolutionise the tourism and hospitality, namely: real-time, co-creation, data-driven, consumer-centric and experience co-creation.     

Non-linear Gaussian sovereign CDS pricing models

Prior literature indicates that quadratic models and the Black–Karasinski model are very promising for CDS pricing. This paper extends these models and the Black [J. Finance 1995, 50, 1371–1376] model for pricing sovereign CDS’s. For all 10 sovereigns in the sample quadratic models best fit CDS spreads in-sample, and a four factor quadratic model can account for the joint effects on CDS spreads of default risk, default loss risk and liquidity risk with no restriction to factors correlation. Liquidity risk appears to affect sovereign CDS spreads. However, quadratic models tend to over-fit some CDS maturities at the expense of other maturities, while the BK model is particularly immune from this tendency. The Black model seems preferable because its out-of-sample performance in the time series dimension is the best.     

双选信道下一种基于混沌交织的FBMC系统

高速移动环境下，无线信道具有时频双选性衰落的特性，使得滤波器组多载波(Filter Bank Multi-carrier，FBMC)系统产生长突发差错。将一种基于Baker映射的混沌交织算法应用在滤波器组多载波系统中，根据混沌密钥对发送数据进行分块和重新排列，按照Baker映射规则完成数据交织。此方法可以将长突发差错变为单突发差错，结合卷积编码能有效地纠正双选信道产生的长突发差错。仿真结果表明，在双选择信道中，基于混沌交织的滤波器组多载波系统误比特率性能优于传统基于块交织的滤波器组多载波系统。     

Rural credit and the time allocation of agricultural households: The case of PRONAF in Brazil

This paper evaluates the impact of Brazil's National Program to Strengthen Family Farming (PRONAF) on the time allocation of household members. We use data from the 2014 Pesquisa Nacional por Amostra de Domicílios, and we apply propensity score methods to complex surveys recently recommended in the literature. We find that PRONAF helps to increase focus on agricultural activities, but it also stimulates female partners to engage in unpaid work. The results show significant effects of PRONAF on child labor and on the gender‐specific division of labor within households, although it does not have the usual adverse effects of rural credit programs on school attendance.     

Do investors actually value sustainability? New evidence from investor reactions to the Dow Jones Sustainability Index (DJSI)

Research Summary: Research exploring investor reactions to sustainability has substantial empirical limitations, which we address with a large‐scale longitudinal financial event study of the first global sustainability index, DJSI World. We examine investor reactions to firms from 27 countries over 17 years that are added, deleted, or continue on the index. We find that once relevant controls and comparisons to observationally equivalent firms beyond the index are included, DJSI events have only limited significance and/or materiality. Nonetheless, investors' valuation of sustainability around the world has evolved over time, involving diminishing reactions to U.S. firms and increasing benefits, particularly of continuation on the index, over time. The study highlights the importance of careful analysis and longitudinal global samples in making inferences about the financial effects of social performance. Managerial Summary: The debate about how investors perceive corporate social responsibility (CSR) predates Milton Friedman's famous statement that the only social responsibility of business is to increase profits. Although extensive research has studied whether sustainability contributes to financial performance, we have yet to understand whether investors believe it pays off. This financial event study of reactions to the addition, continuation, and deletion from DJSI World, the first global sustainability index, shows that investors care little about DJSI announcements. Nonetheless, there is some evidence that global assessments of sustainability are converging and that investors may increasingly be valuing continuation on the DJSI, suggesting that firms may gain at least limited benefits from reliable sustainability activities.     

Changes in airport operating procedures and implications for airport strategies post-COVID-19

Covid-19 is demanding a lot of changes in the realm of our daily lives. The aviation industry is also facing unprecedented changes in the management environment. Financial tensions across the sector are rising. This study suggests that the airport strategy's direction focusing on commercial revenue management. After Covid-19, safety and hygiene will be the top priority. As a result, changes in airport operating procedures are inevitable. The most noticeable difference will be the strengthening of the verification process for passengers' health conditions. Dwell time increase can be the by-products. This study identifies a dwell time increase has a more significant impact on increasing the existing purchasers' spending than creating new buyers. Airport operators can introduce a service differentiation perspective, such as a dedicated service, to utilize the current buyers' dwell time more faithfully. Also, the rise of online channels requires airport operators to change sales strategies, reinforcing emotional promotion to stimulate impulse buyers' willingness-to-buy. Before Covid-19, there was little effort to reconcile operation policies and commercial revenue despite the growing importance of revenue management. However, now it is time to change. Pre-Covid-19, passengers were advised of using off-airport processes, such as online check-in and mobile boarding passes. Now, getting passengers to the airport quickly and securing their dwell time can be financially more beneficial. It is necessary to incorporate the commercial revenue perspective into operation policies post-Covid-19 actively. Our finding indicates that even a passenger with solid purchasing power may lose the purchasing intention when assigned to an unfavorable gate or terminal. Airport operators need a better understanding of passenger and flight characteristics when determining operation policy, such as gate allocation or membership services.     

Correlated daily time series and forecasting in the M4 competition

We participated in the M4 competition for time series forecasting and here describe our methods for forecasting daily time series. We used an ensemble of five statistical forecasting methods and a method that we refer to as the correlator. Our retrospective analysis using the ground truth values published by the M4 organisers after the competition demonstrates that the correlator was responsible for most of our gains over the naïve constant forecasting method. We identify data leakage as one reason for its success, due partly to test data selected from different time intervals, and partly to quality issues with the original time series. We suggest that future forecasting competitions should provide actual dates for the time series so that some of these leakages could be avoided by participants.