Google Mobility Data Provides Us With A Data-Based Proxy Tool To Assess The Efficiency Of A Lock Down And The Verdict For Australia Is… Not GOOD Allan Greenwood Follow Apr 4 · 5 min read

Disclaimers. I have a background in Science and have done extensive reading of various studies, but this does not make me an expert and this article attempts to present data and everyone should draw their own conclusions. Links to the data I have used is included at the bottom of the article

Where Are We At?

At this point in time we know lots about COVID-19 however we still have numerous gaps in our knowledge.

· We know that a hard lock-down can stop the virus.

· We also know that reporting of both cases and deaths in the real world has significant challenges.

The number of cases being reported is dependent on Virus Spread and Testing Penetration. Testing Penetration varies significantly by country and significantly distorts the number of cases present in a country. Given this deaths are the only true way to track the spread and the successes of mitigating activities.

However, Deaths have more chance of capturing a consistent picture so I will be using them in this analysis. As testing improves globally this will change.

Hard Lock Downs Work

A hard lock down as shown by China can stop COVID-19. Italy and Spain are showing similar levels of success.

It is important to remember that when lock-down occurs the people who have just caught the virus are still in the incubation period. So, there will be a further 5 days till symptoms then over a week till hospitalization (if required) and then even more time till fatality occurs. On average there is a 21-day delay from lock-down to the death rate peaking based off analysis of individual cases presenting to hospital.

As the above Graph shows China and Italy had similar behavior post lock-down and, in both cases, the exponential growth of deaths stopped at around day 21 and then started to decrease after a brief plateau.

Italy’s Lock-Down On The 8th March Is Visible In Google Mobility Data

From the Google Mobility Data report you can see change in behavior occurring due to fear of the virus followed by an abrupt decease once the lock-down went into effect.

The Data shows that after lock-down the visits and time spent at Public Places, Public Transit and even Grocery Shopping dropped by ~90%. Time spent in workplaces also decreased by 63 percent.

Australia’s Lock Down Is Having Less Impact

Australia introduced their lock-down gradually and the cumulative impact of all these changes can be seen on the 29th March data point.

Unlike Italy, Australia has only reduced public space use by ~ 40 percent, Public Transport by 58% and workplaces by 33 percent.

In theory this change in behavior of approximately 40 percent should in turn reduce R0 from its starting estimate of 2.5 by up to 40 percent ( i.e. to 1.5). Potentially this reduction in conjunction with increased hand washing and social distancing in the workplace may be enough to reduce the COVID-19 virus spread to the point where it is no longer exponential.

Australia’s mobility change is sufficiently different from Italy (and Spain and France’s Lock Downs) that Australia cannot assume we will get the successful results Italy has already achieved from its Lock-Down.

What Other Countries Could Australia Learn From

The good news is that there are countries / American States that might provide extra evidence to enable Australia to change our approach before the hard data from our own lock-downs come through.

From Google Mobility Data California’s lock-down looks to have a similar level of mobility changes to Australia’s and occurred 4 days earlier. If we do the dangerous assumption that Australia is close to California on a cultural / social level then we can draw lessons from the success or lack of success of California as it is lock-down appears to be similar to what Australia has managed.

California Mobility Data

These percentages are on par with Australia. Therefore, we can watch California’s death rates and draw some lessons which are relevant for Australia. If the lock down is successful deaths should start flat lining in 10 days (i.e. Mid-April) then we can be comfortable about Australia’s level of lock-down.

Conversely if California’s death toll keeps increasing beyond the 15th of April it will be a signal that it is likely that additional lock-down measures will be required in Australia.

Based off the graph above Australia should be concerned if Californian death toll goes beyond 80 per day and shows increasing daily deaths after the 15th of April.

Other Observations

· Sweden had 69 deaths on the 2nd of April. Their mobility data shows very low social distancing reductions of 20 percent in the workplace, 24 percent in retail and recreation but with parks showing a 43 percent increase. Their situation could ugly very quickly.

Links

Cumulative Cases and Deaths Data

https://github.com/CSSEGISandData/COVID-19

Google Mobility Data

https://www.google.com/covid19/mobility/

Individual US state deaths

https://en.wikipedia.org/wiki/2020_coronavirus_pandemic_in_New_York_(state)

https://en.wikipedia.org/wiki/2020_coronavirus_pandemic_in_California