Coronavirus

In this paper (PDF), we propose a continuous-time stochastic intensity model, namely, two-phase dynamic contagion process (2P-DCP), for modelling the epidemic contagion of COVID-19 and investigating the lockdown effect based on the dynamic contagion model introduced by Dassios and Zhao (2011). It allows randomness to the infectivity of individuals rather than a constant reproduction number as assumed by standard models. Key epidemiological quantities, such as the distribution of final epidemic size and expected epidemic duration, are derived and estimated based on real data for various regions and countries. The associated time lag of the effect of intervention in each country or region is estimated. Our results are consistent with the incubation time of COVID-19 found by recent medical study. We demonstrate that our model could potentially be a valuable tool in the modeling of COVID-19. More importantly, the proposed model of 2P-DCP could also be used as an important tool in epidemiological modelling as this type of contagion models with very simple structures is adequate to describe the evolution of regional epidemic and worldwide pandemic. 

You can also find the paper in a HTML version. 

How many people in Britain have already been infected with the coronavirus? The truth is, we don’t really know. Yet, this is a very important number because, without it, it is difficult to properly assess the severity of the virus, its likely trajectory, and the consequent burden on health and social care systems. Read more in this insightful blog post by Professor Jouni Kuha and Professor Patrick Sturgis. 

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Who breaks lockdown rules, ask Patrick Sturgis, Jonathan Jackson and Jouni Kuha? In this blog called 'Lockdown scepticism is part of the Brexit divide', they discuss lockdown compliance and lockdown scepticism on the basis of evidence from a new random sample survey.

Professor Piotr Fryzlewicz has worked on some trend estimates and forecasts in relation to COVID-19:

https://pfryz.shinyapps.io/covid-19/ 

https://pfryz.shinyapps.io/covid-19-deaths/

Professor Clifford Lam has written a short summary below on his work regarding COVID-19.

Objective:

The research is on modelling the time evolution of the spillover effects – or, the spatial linkages on the rate/number of infections/deaths, across different countries in Europe or different regions in UK as restrictions of movements and closure of businesses are imposed over time.

Why is such a modelling important? Traditionally such spillover effects are specified by a researcher, and other aspects of a spatial econometric model are estimated based on the specifications. Such a traditional method assumes that we have correctly specified all spillover effects between each pair of regions, which is in fact an overwhelmingly difficult task in itself. Moreover, it is also assumed constant, which is of very limited use for situations such as COVID-19, where the dynamics of such spillover effects can change based on policy changes.

With our modelling of changes of spillover effects over time using COVID-19 data, we can trace back the effectiveness of the policies implemented in different countries and regions from our data analysis. Over a longer time horizon, we will also be able to trace how the reduction in movement of people affected regional integration and economic outcomes.

The above can in fact be used for broader regional science studies. The effects of economic integration across Europe from the effects of Brexit, for example, can be studied using our method. 

What will be done?

Since the modelling of time evolution of spatial linkages is completely new, we first need to develop the corresponding spatial model for this. Lam and Souza (2019) has successfully analyse a model where spatial linkages can be estimated from data with inference tools available as well. The model lays down a solid foundation for an extension of modelling time evolution of spatial linkages, and the necessary theoretical analysis for the development of inferencing tools. R package will be developed for the purpose, adding with visualisation of how the spatial linkages, as a network, changes over time.