A game-theory analysis of electric vehicle adoption in Beijing under license plate control policy

To reduce traffic congestion and protect the environment, license plate control (LPC) policy has been implemented in Beijing since 2011. In 2019, 100,000 vehicle license plates were distributed, including 60,000 for electric vehicles (EVs) and 40,000 for gasoline vehicle (GVs). However, whether the current license plate allocation is optimal from a social welfare maximization perspective remains unclear. This paper proposes a two-level Stackelberg game, which portrays the interaction between vehicle applicants and the government to quantify the optimal number of EV license plates under the LPC policy in Beijing. The equilibrium number of EV license plates derived from the Stackelberg model is 58,800, which could increase the social welfare by 0.38%. Sensitivity analysis is conducted to illustrate the impact of important influential factors — total license plate quota, vehicle rental fee, and energy price — on EV adoption. The LPC policy under COVID-19 is also studied through a scenario analysis. If the government additionally increases the total quota by 20,000, 24% could be allocated to GV and 76% to EV. One third reduction of the current vehicle rental fee could increase EV license plates by 10.5%. In terms of energy prices, when gasoline price is low, reducing electricity prices could contribute to EV adoption significantly, while that effect tapers off as gasoline prices increase.

Worldwide association of lifestyle-related factors and COVID-19 mortality.

BACKGROUND: Several lifestyle-related factors, such as obesity and diabetes, have been identified as risk factors for Coronavirus disease 2019 (COVID-19) mortality. The objective of this study was to examine the global association between lifestyle-related factors and COVID-19 mortality using data from each individual country. METHODS: The association between prevalence of seven lifestyle-related factors (overweight, insufficient physical activity, smoking, type-2 diabetes, hypertension, hyperlipidaemia, and age over 65) and COVID-19 mortality was assessed by linear and multivariable regression among 186 countries. The cumulative effect of lifestyle-related factors on COVID-19 mortality was assessed by dividing countries into four categories according to the number of lifestyle-related factors in the upper half range and comparing the mean mortality between groups. RESULTS: In linear regression, COVID-19 mortality was significantly associated with overweight, insufficient physical activity, hyperlipidaemia, and age ≥65. In multivariable regression, overweight and age ≥65 demonstrated significant association with COVID-19 mortality (p = .0039, .0094). Countries with more risk factors demonstrated greater COVID-19 mortality (P for trend <.001). CONCLUSION: Lifestyle-related factors, especially overweight and elderly population, were associated with increased COVID-19 mortality on a global scale. Global effort to reduce burden of lifestyle-related factors along with protection and vaccination of these susceptible groups may help reduce COVID-19 mortality.

COVID-19 reinfection: a rapid systematic review of case reports and case series.

The COVID-19 pandemic has infected millions of people worldwide and many countries have been suffering from a large number of deaths. Acknowledging the ability of SARS-CoV-2 to mutate into distinct strains as an RNA virus and investigating its potential to cause reinfection is important for future health policy guidelines. It was thought that individuals who recovered from COVID-19 generate a robust immune response and develop protective immunity; however, since the first case of documented reinfection of COVID-19 in August 2020, there have been a number of cases with reinfection. Many cases are lacking genomic data of the two infections, and it remains unclear whether they were caused by different strains. In the present study, we undertook a rapid systematic review to identify cases infected with different genetic strains of SARS-CoV-2 confirmed by PCR and viral genome sequencing. A total of 17 cases of genetically confirmed COVID-19 reinfection were found. One immunocompromised patient had mild symptoms with the first infection but developed severe symptoms resulting in death with the second infection. Overall, 68.8% (11/16) had similar severity; 18.8% (3/16) had worse symptoms; and 12.5% (2/16) had milder symptoms with the second episode. Our case series shows that reinfection with different strains is possible, and some cases may experience more severe infections with the second episode. The findings also suggest that COVID-19 may continue to circulate even after achieving herd immunity through natural infection or vaccination, suggesting the need for longer-term transmission mitigation efforts.