Between Geography and Demography: Key Interdependencies and Exit Mechanisms for Covid-19

Antonio Scala; Andrea Flori; Alessandro Spelta; Emanuele Brugnoli; Matteo Cinelli; Walter Quattrociocchi; Fabio Pammolli

Our approach contributes to the extant literature on the trade-offs between a mitigation scenario, aimed to slow down the epidemic contagion, and a suppression scenario, consisting on lowering the risk of contagious while maintaining it indefinitely [8, 9, 10] . Our projections show that an anticipated lockdown just shifts the epidemic in time, with a delay proportional to the anticipation time and grows with the strength of the lockdown. Moreover, beyond a critical lockdown strength, while at the beginning the epidemic seems to be quelled, it fully recovers its strength as soon as the lockdown is lifted. If we consider regional mobility flows, due to the sparsity of the mobility matrix, epidemics develop independently in different regions once the epidemic is started. We postulate that the sparsity of the inter-regional mobility matrix could be responsible of the delays observed among different regions and that the same consideration may apply to explain the independent dynamic of the epidemic spreading in different countries. Finally, if we add social contact heterogeneity on different age classes we find that the structure of social contacts is of primarily importance for avoiding an underestimation of the post-lockdown effects and that age class based strategies can help to mitigate rebound effects with milder strategies.