Matt Kilcoyne is Head Of Communications at the Adam Smith Institute.

During a crisis, a lot of drawn-out debates usually had over months, if not years or decades, take place in days. This has long-run consequences.

Europe has gone from burqa bans to compulsory face coverings; all those who sleep rough on our streets have been offered immediate shelter ahead of dealing with addiction. We are now on the cusp of making a decision about a new tradeoff between privacy and security. To deal with COVID19 in the next stage, we have to make a decision on the latter issue, because of new tracing apps.

The issue of privacy – once, for many, just an academic debate or discussed at think tank events on the fringes of party conferences –  is now at the forefront of policy-making, with very real consequences for our lives and livelihoods.

Matt Hancock is likely to meet the 100,000 tests per day target by the end of the month. This will be thanks to the great work of James Bethell in bringing on private labs, Amazon warehouses and Royal Mail postmen into the national effort.

We now need to make sure that you know if you’ve been near enough to someone who has tested positive, so that you can isolate and be tested yourself. The tracing app that the Health Secretary has announced is coming is aimed at reducing the transmission rate, and helping more of us back to work and family lives.

We can track and trace manually — but, even with the most skilled staff, we end up reliant on often erring human memory. An app using Bluetooth to show which other people we’ve been near for an extended period of time could help overcome this issue.

Other countries – such as Taiwan, Singapore, Australia and Germany – have developed or are developing these apps, which will track those who have been infected and let other users know to get tested themselves. To varying degrees of success: most of which comes down to that academic debate around privacy.

When governments make it mandatory to hand over large amounts of data, you increase the cost that people associate with the app’s usefulness. I’ll be blunt: right now I don’t care about your view of those that value privacy more or less than you do — the reality is that some people do.

These people just won’t download the app, have their phones switched off, or leave their phone at home. An app that’s not helpful, money down the drain at a time we can scarce afford to waste it, and trust lost is a bad investment.

Epidemiologists estimate that we’ll need about 60 per cent of people to download the app for it to be effective. Around 95 per cent of us have a mobile phone, with about 80 per cent owning a smartphone. As a result, three quarters of people with a smartphone need to download the tracing app.

We can learn from elsewhere’s mistakes. South Korea made a lot of information public that allowed the nation’s amateur social media detectives to publicly identify individuals infected — so others avoided getting tested at all. In Singapore, the way the app operates precludes its operation on Apple devices and some Android phones, and data it hands to the Ministry of Health is effectively a big list of names of the infected. Neither are great outcomes for many people, and explain why around just one in five people have downloaded the app.

Fortunately, a solution has come forward that allows epidemiologists and Health Departments to access the data they need, while ensuring there’s enough downloads to make it a useful app in the first place: a decentralised solution.

DP-3T might sound like something out of Star Wars, but it’s actually more about countering the risk of a viral Minority Report. It places trust in citizens’ self interest over their health and the health of their loved ones. Apple and Google, who continue to dominate your phone’s user systems, have reputations to lose over what they allow on them.

The irony of the great satans of recent political years being more married to privacy, knowing that their commercial reputations are on the line over it, while governments the world over have been happy to throw that away should not be lost.

Companies get this: if their reputation over something this important is trashed, then they will feel the wrath of millions of consumers switching to competitors almost overnight. Governments and politicians have far longer between decisions and voters’ choices.

Apps based on the DP-3T framework store data on your personal phone. It also anonymomises the data, by sending a random jumble of letters and numbers rather than an identifiable number to the central server.

hese change every day, making you even more difficult to identify. Your use keeps others safe, but it doesn’t jeopardise your own or set dangerous precedent. Without trust, you only have non-compliance and ineffectiveness, potentially a second peak and economic ruin. This is the path down which Hancock’s new app should tread.

If we use this privacy-saving solution we have a chance to turn the tide. Kudos, too, to the unnamed official behind the other decision too that you’ll be able to order tests via the app.This makes it even more worthwhile to download it. Privacy and efficacy are not polar opposites but they are in balance and decisions over each have consequences.

Perhaps instead of saying we’re following the science, we should be prouder to say that we’re following the logic of the evidence to achieve our goals.