on making NZ COVID Tracer mandatory: we can make participation in record-keeping for contact tracing mandatory - we did when we went into Level 3 the first time back in May last year. We asked businesses to keep records of all their visitors and customers, most of which was...

on pen and paper but some was through apps like Rippl.
I am less convinced that we can make use of the NZ COVID Tracer app mandatory - there are two obvious questions:

The first is one of enforcement, in that it is practically not possible to enforce usage of the app. I think that an unenforced mandate is okay though, if the govt says that it's mandatory then most New Zealanders will follow the rules because they understand that it's important.

We can see that with face masks on public transport in Auckland and on domestic flights - there is no Police enforcement of that rule, but the vast majority of people are following it, and that's good. If we made the app mandatory but unenforced, it would probably drive uptake up

The second question is one of equity and inclusion, in that about 20% of the adult population simply do not have a device that can run NZ COVID Tracer right now. So if you're going to make it mandatory, then there has to be a way for the digitally excluded to participate.

This is a much bigger challenge. There has been some discussion about giving phone vouchers so that people can buy devices, but they will still need help
developing the skills to use those devices, and you still have to figure out internet access and charging batteries, etc.

But we should come back to first principles - what is it that the govt is asking people to do? The govt wants you to keep track of your own movements so that if you test positive for COVID-19 and get interviewed by a contact tracer, you can say where you have been and when.

Doing this helps contact tracers identify who might have the disease, get them isolated and tested, and stop them from spreading the disease further. The app is a good way to do this, but having your own up-to-date pen and paper diary is good for this purpose too.

The other thing the govt wants is for your locations or interactions with other people to be stored on your device, so that the govt can issue exposure notifications for places or devices, so that you can be notified of potential exposures to COVID-19 and take action more quickly

That role cannot be easily replaced by other methods, pen-and-paper registers at venues is just not as good and carry other privacy risks. The government is also going to do media announcements about exposures, there will still be manual contact tracing, there are multiple tools.

The advantage of the app is speed, but the other layers of defence are also important and supplementary. I can understand why making the app mandatory appears to be an easy fix to a problem, but there are a lot of considerations that need to go into that policy decision.

One of the most critical factors in the response to COVID-19 is trust in government and public health officials. I don't think that making the app mandatory is going to help with trust if the govt doesn't also convince people that using the app will make a difference.

If making the app mandatory makes some people trust the government less, and then they don't get a test when they should or they don't isolate when they should, then we are creating a much, much bigger problem bc the impact of that is greater than getting more people on the app.

The govt has to be pretty careful about pushing things too far. We mostly complied with the lockdown because we trusted the government that it was the right decision, in part because it's pretty obvious that going into lockdown reduces the spread of the virus, but also...

... because the govt explained what they were going to do and why, in the days and weeks leading up to the lockdown. I think the theory and the modelling shows that using digital contact tracing can help with reducing the spread of the virus...

... by cutting off the chains of transmission more quickly, but people need to be reminded about that underlying reasoning for why scanning QR codes is important, why having Bluetooth Tracing on is important, before we think about making it mandatory to use the app.

In short, I can see the args for making NZ COVID Tracer mandatory, but there are many complicated risks. I don't have an easy rec for govt to "just do it" or "don't do it". But I hope people will use the app voluntarily because it supports contact tracing against COVID-19. /fin

BTW, it's still mandatory for all businesses to display a QR Code while we're still at Level 1, with infringement fees or court fines possible. So if you see a shop missing a QR code, please ask them about it (nicely). See some good practice here: https://twitter.com/andrewtychen/status/1348830608399626240?s=20