| 1. Introduction and Overview |
| Table 1. | Cumulative Cases and Deaths (January 5, 2020–February 11, 2024). | 2 |
| 2. The Heterodox Economics of Passenger Airlines, Plagues, Pandemics, and Other Unhealthy Occurrences | | |
| Table 1. | Timeline of Major Epidemics and Pandemics Since 1980. | 24 |
| Table 2. | Comparison of 2017–2018 Seasonal Influenza Season to the COVID-19 Pandemic in the United States. | 27 |
| Table 3. | State Support Rendered to Airlines Between January and August 2020 by Order of Aggregate Amounts. | 37 |
| 3. Nonmarket Strategies of Airlines in a COVID-19 World and Beyond |
| Table 1. | Selected European Airlines Bankruptcies. | 54 |
| Table 2. | Financial Support Offered to Select European Airlines. | 56 |
| 4. COVID-19 Uncertainty and the Cross-Sectional Stock Returns of Airlines |
| Table 1. | Descriptive Statistics on Daily Return. | 75 |
| Table 2. | Empirical Results of Eq. (1). | 79 |
| Table 3. | Descriptive Statistics. | 85 |
| Table 4. | Bivariate Regression of Pandemic Beta on Airline Attributes. | 86 |
| Table A1. | Empirical Results for Eq. (2). | 89 |
| Table A2. | Empirical Results for Eq. (3). | 90 |
| 5. COVID-19 and Airlines: A Final Analysis Through the Lens of Complex Networks | | |
| Table 1. | The Calculation Process for Betweenness Centrality of Node 1 (j < k) in Fig. 2. | 99 |
| Table 2. | Top 50 Airlines by Fleet Sizes, Sorted by Regions (Airlines Analyzed in This Study Are Highlighted in Bold). | 103 |
| 6. Rebuilding Airline Networks in the Post-COVID-19 Era: New Network Configurations in Europe? | | |
| Table 1. | Variations in Total Seats Offered by Business Model and Type of Operation Between Pre- and Postpandemic Periods (09/2019 vs. 09/2022). | 124 |
| Table 2. | Variation Number of Competitors per Route (09/2019–09/2022). | 128 |
| Table 3. | Share of Routes by Period of Operation (09/2019–09/2022). | 130 |
| 7. Competition Between Full-Service Carrier and Low-Cost Carrier and the Impact of COVID-19 Pandemic: Evidence From China | | |
| Table 1. | Profile of Current Chinese LCC as of 2023. | 150 |
| Table 2. | Comparison of Unit Operating Costs Between Spring Airlines and the Big Three Airlines. | 151 |
| Table 3. | Comparison of Traffic Between Spring Airlines and the Big Three Airlines. | 152 |
| Table 4. | The Rank of City Air Passenger Traffic. | 164 |
| Table 5. | The Number of Different Routes Before and After the Pandemic Outbreak. | 166 |
| Table 6. | The Ratios of Different Types of Routes When Comparing the Level of December 2022 With December 2019. | 167 |
| Table 7. | Comparison of FSC–LCC Market Contact Before and After the Pandemic. | 168 |
| 8. Measuring the Risk of COVID-19 Spread via the US Air Transportation Network |
| Table 1. | Descriptive Statistics, 2020. | 182 |
| Table 2. | Descriptive Statistics, 2021. | 183 |
| Table 3. | Top 20 at-Risk Destination Counties, 2020 Versus 2021. | 188 |
| Table 4. | Correlation Table. | 190 |
| Table 5. | Travel Risk Regression Results Accounting for County- and State-Route Fixed Effects. The Dependent Variable is the Relative Risk at Destination (Rj). | 193 |
| Table 6. | Travel Risk Log-Log Regression Results Accounting for State-Route Fixed Effects. The Dependent Variable Is Natural Log of Relative Risk at Destination (ln(Rj)). | 195 |
| Table 7. | Travel Risk Regression Results. The Dependent Variable Is the Risk Spread From Origin to Destination Counties (rij). | 198 |
| Table 8. | Travel Risk Regression Results Accounting for County- and State-Route Fixed Effects. The Dependent Variable Is the Risk of COVID-19 Spread From Origin to Destination Counties (rij). | 200 |
| Table 9. | Travel Risk Log-Log Regression Results. The Dependent Variable Is Log of Risk of COVID-19 Spread From Origin to Destination Counties (ln(rij)). | 201 |
| Table 10. | Travel Risk Log-Log Regression Results Accounting for County- and State-Route Fixed Effects. The Dependent Variable Is the Natural Log of Risk of COVID-19 Spread From Origin to Destination Counties (ln(rij)). | 203 |
| Table 11. | 2SLS Regression Results. The Dependent Variable Is the Relative Risk at Destination (Rj). | 206 |
| 9. Effects of the COVID-19 Pandemic and Related Policies on Airport Short-Term Costs |
| Table 1. | Descriptive Statistics, 50 US Airports, 2012–2021. | 224 |
| Table 2. | ITSUR Estimation Results of Translog Cost Function With Negative Attributes, COVID-19 Cases, and Related Policies, 50 US Airports, 2012–2021. | 226 |
| Table 3. | Characteristics of Representative Airports for Pre-COVID-19 and COVID-19 Periods, Full Sample, 2012–2021. | 229 |
| Table 4. | Decomposition for Percentage Change in Average Variable Costs of Representative Airports for Pre-COVID-19 and COVID-19 Periods, Full Sample, 2012–2021. | 231 |
| Table 5. | Decomposition for Percentage Change in Average Variable Costs of Representative Airports for Pre-COVID-19 and COVID-19 Periods, Large Hubs, 2012–2021, Subtotals. | 232 |
| Table 6. | Decomposition for Percentage Change in Average Variable Costs of Representative Airports for Pre-COVID-19 and COVID-19 Periods, Medium Hubs, 2012–2021, Subtotals. | 233 |
| Table A1. | Airport List. | 243 |
| Table A2. | Data Sources. | 244 |
| Table A3. | Characteristics of Representative Airports for Pre-COVID-19 and COVID-19 Periods, by hub Size, 2012–2021. | 245 |
| 10. COVID-19's Effect on the Technical Efficiency and Productivity of US Airlines: An Industry Sectoral Analysis |
| Table 1. | Descriptive Statistics by Service Type From 2006 to 2021, Mean. | 260 |
| Table 2. | Descriptive Statistics by Service Type During COVID-19 (2020, 2021) and During Pre-COVID-19 (2018, 2019), Mean. | 262 |
| Table 3. | Descriptive Statistics by Service Type in 2020 and 2021, Mean. | 264 |
| Table 4. | Technical Efficiency Scores by Carrier. | 271 |
| Table 5. | Tobit and Fractional Logit Regressions of Technical Efficiency (TE) Scores. | 272 |
| Table 6. | Total Factor Productivity and Its Components by Service Type. | 274 |
| 11. Analysis of the Impacts of COVID-19 on US Airline Schedule Planning and Service Delivery, 2018 to 2022 |
| Table 1. | Business Resilience Measures for China, ECAA, and the United States. | 295 |
| Table 2. | Business Resilience Measures for US Airport Categories. | 296 |
| Table 3. | Business Resilience Measures for Top 10 US Passenger Airlines. | 297 |
| Table 4. | Monthly Schedule Differences by Airport Category: Summary Metrics. | 300 |
| Table 5. | Summary and Comparative Statistics for Top Four Airlines, 2018–2022. | 304 |
| 12. Starting From the Backhaul: Evaluating the Effects of COVID-19 on Airline Traffic Flows |
| Table 1. | Output Measures (RPM and RFTM, in Millions) for Air Carriers by Country. | 326 |
| Table 2. | Carrier Continent/Country and COVID-19 Travel Restrictions. | 330 |
| Table 3. | Fronthaul RFTM (in Millions), Air Carriers by Country, and COVID-19 Travel Restrictions. | 331 |
| Table 4. | Backhaul RFTM (in Millions), Air Carriers by Country, and COVID-19 Travel Restrictions. | 331 |
| Table 5. | Nonparametric Breakpoints in Fronthaul and Backhaul Load Factors by Carrier Continent. | 336 |
| 13. Global Airline Employment and the COVID-19 Pandemic: Impacts, Comparisons, and Implications for the Future |
| Table 1. | Change in Total Employment for US airlines From February 2020. | 356 |