Is the cure worse than the disease? The Times claimed today: “If the coronavirus lockdown leads to a fall in GDP of more than 6.4% more years of life will be lost due to recession than will be gained through beating the virus.” It’s hard to know where to start with this nonsense. It’s based on a paper currently under review at a journal entitled Nanotechnology Perceptions, which simply assumes that a fall in GDP translates mechanically and directly into a fall in life expectancy.

It’s this sort of reasoning that appears to be leading President Trump to call for an early end to restrictions in the US, claiming that far more people would die of suicide from a “terrible economy” than from the virus.

But the premise is simply wrong. A recession – a short-term, temporary fall in GDP – need not, and indeed normally does not, reduce life expectancy. Indeed, counterintuitively, the weight of the evidence is that recessions actually lead to people living longer. Suicides do indeed go up, but other causes of death, such as road accidents and alcohol-related disease, fall.

So at the most basic level, this argument ignores what the evidence says. But perhaps more importantly, the idea that the way to minimise the economic damage is to remove the restrictions before they’ve done their job – definitively suppressing the spread of the virus – is a terrible one.

Does anyone believe that, whatever the government said, we could get back to “normal”, or something close to it, any time soon? If we were all allowed to return to work, many or most of us would, quite rationally, choose not to, for fear of catching the virus. And if, as the scientists predict, the result of loosening the restrictions was an acceleration in infections, then pretty soon many firms would simply stop functioning, as workers became sick, or had to stay at home to look after family members.

More broadly, restoring the economy to normal requires, above all, confidence. Amid continuing uncertainty both about their own finances and the wider economy, households won’t spend and businesses won’t invest. And that simply isn’t going to happen until the spread of the diseases has been contained.

So there is no tradeoff here. Health and economic considerations point in exactly the same direction in the short term. Do whatever it takes – and whatever it costs – and do it now, in the interests both of our health and our collective wealth.

But what comes next? It is entirely reasonable to point out that serious damage to the economy, if it persists over the longer term, will reduce our welfare and maybe even – as austerity and its aftermath have done – life expectancy. The last 10 days have seen universal credit claims rise more than five-fold, to half a million, while YouGov data suggests that 2 million people may have lost their job. The recession is already here.

But this need not, and should not, be permanent. The risk here is that we allow the inevitable fall in GDP that results from shutting down the economy to drive firms out of business and workers into long-term unemployment. And there is nothing inevitable at all about this.

After all, many European countries, such as France or Italy, probably, see their GDP fall by 10% or 20% or so in absolute terms every August when workers take their summer holidays. No one notices – the numbers are “seasonally adjusted” to take account of holidays, which means it doesn’t show up in the published data – nor does it do any damage. Workers continue to be paid, and businesses don’t go bust just because they’re not making any money. Come September, everyone gets back to work as normal.

Of course this is very different – that won’t happen automatically with Covid-19. The impacts are more widespread and long-lasting – and we don’t know how long – than an enforced extra holiday. But rapid and appropriate action by government can go a long way. Keeping workers in jobs and firms in business needs to be the priority. In the circumstances, the government’s made a good start, although there’s lots more to do.

So what we should be worried about – both from an economic and a health perspective – is not how much GDP falls. It’s going to fall by a lot, and that’s a good thing. If it didn’t – if people were still going to work despite being told not to – then the lockdown wouldn’t be working and we’d still see economic consequences further down the line. It’s what happens to GDP in a year or 18 months that matters.

And the long-term consequences? It wasn’t the sharp fall in GDP in 2008-9 that reduced, over the course of the next decade, life expectancy for the poorest in our society. It was how the government chose to address the economic fallout of the global financial crisis – by underfunding and understaffing the NHS and social care, and by eroding the basic welfare safety net that people depend on when times are hard. As we are now discovering, these were false economies that left us less, not more, prepared for this crisis.

Similarly, if we allow Covid-19 to permanently damage our economic and social fabric, it will be our own fault, not that of the virus. This time we can, and must, do better.

• Jonathan Portes is professor of economics and public policy at King’s College London and a former senior civil servant