For the last two years, one question has been on everybody's lips: "When do we get back to normal?" Countries have tried and failed to lift all their Covid-19 restrictions. Many in Europe have been forced to ramp them up. Others, like ChinaA country in East Asia, home to 1.4 billion people., continue to hide behind closed borders, locking down whenever cases crop up.

In ScandinaviaThe name given collectively to Denmark, Norway and Sweden, three of the northernmost countries of Europe. The three countries have similar languages and political systems., "normal" starts tomorrow, as Sweden lifts Covid-19 regulations. It joins Denmark and Norway in a new approach. People will be encouraged to stay at home if they are ill. No more vaccine passportsMany countries have introduced passes based on vaccination status or recent tests to enter some public spaces and business., curfews, limits on socialising - and no more masks.

About time, say some. Among them is author Ian Miller, who argues that masks have been a collective delusion.

He points out that in the first months of the pandemic, public health experts across the Western world insisted masks did nothing to stop the spread. He thinks after they changed their advice, they never bothered to check whether masks work.

He argues the evidence suggests they do not. For example, Los Angeles has had a mask requirement for most of the pandemic. Yet it has had higher rates than neighbouring Orange CountyA region in southern California forming part of the Los Angeles metropolitan area., which has had no mask requirement for a year.

Others think this does not prove much. The population densityA measure of the number of people within a particular area. It is usually measured by people per square kilometre. of Orange County is about half of LA. Viruses spread more easily in densely-populated areas, because people have more contact. Studies comparing the impact of masks suggest they have an impact on the spread of the disease.

The stakes in this research are high. If other countries follow Scandinavia, they cannot assume they will fare as well. Sweden, Denmark and Norway all have low population densities, high vaccination rates and resilient public health systems. 

These conditions make it harder for the virus to spread. Most other Western countries are more densely-populated, have fewer triple-jabbedMost Western countries have rolled out third booster jabs, intended to increase people's immunity to the Omicron variant. citizens and do not invest as much in their health systems. If abolishing masks does lead to a spike in infections they will struggle to deal with it.

Still others suggest that even if masks did have no direct effect, they could still serve some purpose. Wearing a mask is a reminder to keep abiding by other Covid-19 measures, like ventilating spaces and maintaining social distancing. And it reassures others that we are taking these duties seriously.

Yes: Masks have become a culture warAn internal conflict over a country's values. The term is a translation of the German Kulturkampf, originally referring to a struggle between the state and the Catholic Church in the late nineteenth Century. issue, dividing countries down the middle. Now it seems they have done little to stop the spread of the virus. They have done more harm than good.

No: Although a lot of health experts initially got it wrong, there is solid evidence that masks do slow the spread of Covid-19. They have likely saved millions of lives, and we should keep wearing them.

Or... The main benefit of masks is not restricting the spread of the disease, but acting as a social signal to others that we take their health seriously. They helped us stay united in the dark days of the pandemic.