On the global time evolution of the Covid-19 pandemic: Logistic modeling

• Published in: Technological forecasting & social change 2022-02, Vol.175, p.121387-121387, Article 121387
• Main Authors: Miranda, L.C.M., Devezas, Tessaleno
• Format: Article
• Language: English
• Subjects: Case studies; Continents; Coronaviruses; COVID-19; Evolution; Forecasting; Pandemics; Qualitative analysis; Qualitative research
• ISSN: 0040-1625; 1873-5509; 0040-1625
• DOI: 10.1016/j.techfore.2021.121387

•This article presents a global time evolution analysis of the Covid-19 pandemics, through which it is shown that it has unfolded globally as a succession of six multi-logistic phases or spurts, each with its own characteristic duration and intensity.•The spectral analysis of the residuals of the total number of cases data fitting evidenced “hidden” oscillatory mechanisms driving the pandemics, dominated by two modes: a sharper one at a higher frequency with a period of 7 days, and a broad low frequency band with a mean period of roughly 40–50 days.•It is demonstrated that the short period mode is due to a "weekend effect", while the long period mode may be associated with the time difference of the spread of the disease among the several continents.•The detailed study of the epidemics in Portugal demonstrates the positive consequences of preventive sanitary measures, as well as how disastrous it may be the absence of such measures due hesitations and/or political positions. It's clearly demonstrated that the concentrated effort in vaccination really contributes to reducing the number of daily cases and deaths.•In the final discussion it is discussed a strong hypothesis (Gelfand's cultural tightness-looseness model) explaining the different behavior of the spreading of the Covid 19 pandemics among different countries and continents, and it is also briefly discussed the forecasting capacity of the presented model. In this article it is presented a multi-logistic model to describe the time evolution of the Covid-19 pandemics. The model is not intended as paragon for the accurate prediction of the future number of people infected, but instead as a useful phenomenological approach for a comprehensive understanding of the pandemic development, able to uncover some hidden aspects of its unfolding. Our results, using OWID data of total cases and daily cases of Covid-19 from March 12, 2020, up to September 27, 2021, brought to light that the pandemic has unfolded globally as a multi-step logistic, namely six logistic phases, each with its own characteristic duration and intensity. Moreover, it is demonstrated how differently the pandemics spread among different countries and continents. The methodology is tested regarding its ability of forecasting, and is demonstrated that it works well in the range of circa 30 days within a margin of less than 3% error while a given phase is still in development. The case study of Portugal demonstrates the benefit of preventive