IMPORTANT STUDY: up to 50% of Americans wouldn't use a contact tracing app with privacy & accuracy problems. Research by: @eredmil1 et al. Quick THREAD. https://arxiv.org/abs/2005.04343 

Americans least trusting of sharing their movements to their EMPLOYER. Actually worse than Gov. More trust in sharing with a nonprofit or tech company…

Makes sense. Peoples privacy concerns are not generic. They track perceived likelihood of harm. For most ppl, employer can do a lot more harm to them than an NGO.

People's decisions about whether to install an app show that they care about public health. The more likely an app is to be accurate, and helpful, the more people will install it.

Wow, look at that odds ratio! Knowing someone who died from #COVID19 makes ppl 5x more likely to accept an app with some accuracy issues.

Looks like Americans especially worried about false negatives (i.e. a non-tracked #COVID19 exposure). Makes sense... So I think we can draw some tentative lessons....

Looks like there could be a contact tracing app death spiral. STEP 1: app loses users trust b/c of privacy and accuracy issues. STEP 2 Greater risk of missed exposure as users stop using. STEP 3: leading to more lost users, more false negatives...

If you get privacy or accuracy wrong at launch, possible you won't recover. Image: users panning and abandoning the inaccurate South Dakota Care19 app.

As employers look for apps to help bring people back to work, they would do well to heed the warning here: collect location data, and generally be untrustworthy, and alienate the people whose participation you need.