Germany’s Covid-19 tracing app won’t work

Life isn’t about finding perfect solutions but making difficult trade-offs. So it is with the contact-tracing apps that are proliferating faster than I can keep up with. In Germany’s newly launched “Corona App”, it has got several trade-offs wrong, and should have learned from the experience of nimbler countries like Singapore.
The goal, of course, is the same for all these apps: not to replace, but to augment and assist human contact tracers in pinging people who’ve been near an infected person. Human beings can only name contacts they know; software can point out strangers who’ve been within aerosol range.
The success of any tracing technology, however, depends on a lot more than its skill at sending “exposure notifications.” Once you get a ping, can you also get easy access to a coronavirus test? Does a social worker follow up to help you quarantine, by arranging for groceries, for example? Do public health officials keep checking in? Based on my experience, Germany and Singapore are both pretty orderly places that do these things well.
But to succeed at actually tracing contacts, any technology must first achieve what economists call network effects, according to which the usefulness of an app increases with the number of people using it. If you’re the only one on the corona app, its utility is zero. If everybody’s on, it’s invaluable. To be reasonably useful, at least three in four people must log on, experts reckon.
So far no voluntary app in the world comes anywhere near that. Even in Singapore, only about one in five residents has been using TraceTogether, which was launched as early as March. In Germany, only about 42% are even considering downloading the new app, according to a poll. What, then, are the factors that might be impeding adoption? One is the relative inconvenience of using an app. Both TraceTogether and Corona App, for instance, use Bluetooth wireless technology to let phones communicate with one another. But keeping Bluetooth enabled drains batteries faster.
The bigger issue is privacy and the perceived creepiness in being surveilled. Here apps across the world vary widely. Are users completely anonymous to the system or can they, directly or indirectly, be identified (as they can in China and South Korea, for instance)? How much control do people retain over their data? And what data, beyond infection status, is being collected in the first place? (In China and South Korea this included payment information.) Finally, will the data eventually be deleted, or could it be used for some other purpose?
This is where the data cultures of Germany and Singapore diverge dramatically. As you’d expect, Germany has opted for maximum privacy on every question down the list. Not only can users opt out at any time, they also remain completely anonymous. They may find out that they’ve recently been within two meters of an infected person for more than 15 minutes, but they won’t know where that was. Being anonymous, they also can’t be contacted, so it’s up to them to call in and report their health status or get instructions for next steps.

—Bloomberg