Overnight curfew will be applied if the incidence of coronavirus cases of 100 new infections per 100,000 inhabitants is exceeded. This is what the concept of the new law on the protection of infections in Germany says. So far, curfew in Germany has been used only selectively.
Other countries use it more extensively: for example France and the Netherlands, but also Turkey, Morocco and Tunisia. In Argentina, there have been more restrictions for half of the citizens since Friday.
The argument in favor of nightclub arrangements is: Infections often occur privately. According to the theory, such contact and thus the spread of the virus by means of evening clock can be reduced.
A majority of Germans will support them if only in exceptional cases they are allowed to leave their homes temporarily at night to combat the pandemic. At the beginning of April, 56% were in favor of the measure in a poll by the polling institute YouGov, 37% were against it. The results are reportedly representative of the adult population.
But is night-time walking even effective?
Reproduction rate decreases
According to a study by researchers, mostly from British universities, a night clock can have a positive effect on the reproduction number of COVID-19. This so-called R-number indicates how many people infect an infected person on average.
According to the study, the night clock can reduce this value by 13%. However, the authors point out that this should be seen as part of a wider range of measures such as restaurant closures and restrictions on private meetings.
So far, the study has only been published as a pre-print, so it has not yet been reviewed by the peer.
Canada as a case study
Canadians have already gained experience with evening clocks in the past year. Since the beginning of January, there has been a nightmare in the province of Quebec in regions that are greatly affected.
When DW asked at the end of March on what scientific basis the decision was based and whether the consequences of the measure would be evaluated, the provincial health ministry could not give a definitive answer. However, it is said: “observational studies show that this measure prevents meetings.”
The statement is supported by a pre-print study later published by several Canadian scientists. This shows that the mobility of the night in Quebec was 31% lower than in neighboring Ontario, which has no evening clock.
A night watch has been in effect in some parts of Quebec since January
Jay Kaufman, an epidemiologist at McGill University in Montreal, Quebec’s largest city, wrote to DW: “Quebec has had stable or declining effects over the past few months, even as other Canadian provinces have increased.” Nevertheless, he can and does not want to attribute the developments only to the evening clock in Quebec, says Kaufman, who was not involved in the study.
Many other factors play a role – such as the vaccination rate, the number of tests per day, whether the lessons take place digitally or at school.
The number of cases has risen again, Kaufman said, after the evening clock was postponed from midnight to 9:30 pm in mid-March due to the change of clocks to summer. “But how these different policies work together and what the unique contribution of each is is something that requires a careful study, not just a vague impression,” says the epidemiologist.
By the way, anyone who is on the street at night without good reason has to pay a fine of 1,000 to 6,000 Canadian dollars (about 670 to 4,400 euros), young people have to pay a fine of 500 dollars.
Politics must be more transparent
In Germany, there has so far been a lack of data for a reliable study, says Professor Christof Schütte, president of the Zuse Institute Berlin, which works in the field of modeling and simulations. According to him, evening clocking can be very effective “if it is really complied with along with the other measures”, he told DW.
Schütte also sees politics as the obligation to communicate more clearly and uniformly. But he fears the effect will only last for a short while, as people would rather meet at different times of the day.
Simulation is like a computer game
Amineh Ghorbani believes that despite such meetings during the day, curfew would have an effect. Ghorbani teaches at the TU Delft in the Netherlands at the interface between computer-based social sciences and engineering. In her work, she uses simulations to study human behavior.
She is working with scientists from France, the Netherlands and Sweden on the ASSOCC project, a simulation in which an artificial society is exposed to the coronavirus pandemic for a year. They use it to test the effectiveness of various coronavirus measures, and according to their own information, they have notified the Swedish and Italian governments.
This society is similar to the computer game “The Sims”, Ghorbani explains in an interview with DW. The people in the simulation have needs like hunger or the desire to see friends. If the desires become very strong, it can mean that they begin to disregard rules.
The result of the simulation: evening clock helps to prevent the number of infections from skyrocketing and can therefore contribute to the protection of the overload of the health system.
But Ghorbani also says that “other than a complete two-week exclusion where things seem to be working out afterwards. Ultimately, a longer period is needed to be effective.” In addition, they are not as effective on their own and therefore need to be combined with other measures.
How effective evening clock is compared to other measures also depends on where you are in the pandemic. In Germany and the Netherlands, the numbers show a new wave of infections. “If you decide to go for a strict lockout, it’s good to have the evening clock with a lockout as well,” Ghorbani explains, referring to the simulation. After three weeks, for example, the exclusion can be relaxed, but the evening clock must remain in place to be able to keep the positive effect of the severe restrictions longer.
France’s experience is not clear
Even in large parts of France, people are not allowed to go out for months without a good reason. The evening clock is sometimes applicable from 20:00, sometimes from 18:00, sometimes from 19:00
Science does not completely agree on the consequences of these restrictions. A group of scientists from Toulouse have found that the night clock can have a negative effect: the evening clock at 20:00 in Toulouse reduced the spread of the virus, but the evening clock at 18:00 made the situation worse. According to the group, the reason for this may be that more people gathered in supermarkets earlier.
A current pre-pressure study by researchers at the French Institute of Health and Medical Research is pushing for night time in principle. Consequently, they were helpful in limiting the spread of the original SARS-CoV-2 strain in January. However, according to the researchers, they, along with other so-called social distance measures, were not sufficient to limit the spread of the more aggressive British mutant B.1.1.7.
Fact check: Anyone who uses or supports curfew as a measure in the coronavirus pandemic would like to point to other countries that are already using it as proof of their effectiveness. So far, however, the data is still scarce.
However, studies and simulations indicate that it can be quite effective under certain circumstances – for example in combination with an exclusion or the restriction of private meetings.
This article has been translated from German.