Anecdotal evidence of the effectiveness of the Italian lockdown

Are Italians are complying with the lockdown aimed at reducing the spread of COVID-19? It’s yesterday’s news that aggregated cell tower location data has been used by Lombardy’s governor to menace harsher measures for those who are out and about without a legitimate reason. Movements of more than 500 meters have reduced by more than 60%, according to this data. This is in agreement with a previous study, in which a team of Italian scientists have used location data from users that had opted-in to a program called “Data for good”, showing how movements between counties reduced by at least 50% nationwide since the lockdown. This perhaps demonstrates how a granular data approach can be used to track the effectiveness of public health policies with limited compromises to individual privacy.

Turns out even website traffic data might be sufficient to draw similar conclusions. I happen to manage a small website that helps people automate a bureaucratic task in Italy; since it has had consistent traffic for the last months it might be a good dataset to look at. The assumption is that since people will be less involved in bureaucratic tasks while forced at home, they would visit the website less after the lockdown. That is indeed the case:

Another question is whether cities with a larger number of cases would see a bigger drops in visits; looking at four major cities (one near the epicenter, the others less affected) with this data that does not seem to be the case:

It would be interesting to model what fraction of the population agreeing to sign up for voluntary tracking is needed to enact finer grained lockdown strategies aimed at confirmed cases and their close contacts. Given how privacy is valued in the EU this might be a difficult task, although things might have changed already.