The massive rise in test intensity during the re-opening of European economies indicates that most countries are now trying to suppress – or even eliminate – the epidemic.
Mitigation? Containment? Herd immunity through infection? Or as little spread of the virus as possible? European governments have struggled finding their paths during the COVID-19-pandemic, and in many countries the official strategies are still unclear.
In some countries, governments and public health officials have disagreed on which strategies were preferable and even viable. Also, the strategies chosen by neighbouring countries may be crucial. It has often been argued that suppressing the epidemic in one country is futile if the neighbors allow wide spread of the virus. Today, becoming isolated as a high-risk area may be an equally justified concern.
Such considerations may explain why European governments have often been hesitant when formulating goals and strategies. But instead of focusing on the countries’ formal strategies, it makes sense to look at what they are actually doing. As it turns out, it is possible to identify clusters of countries that are moving in the same direction.
The positive-rate reveals the strategy
In this article, I compare the coronavirus strategies of European countries based on their testing activity. Rather than looking at the number of tests per million inhabitants, I focus on the share of positive tests among those tested for SARS CoV-2 infection: The positive-rate.
This number says something about how aggressive the test strategy of a country is. Countries with aggressive strategy have low shares of positive results and presumably a low number of undetected cases. They are in control of the epidemic. Countries with higher shares of positive result have more undetected infectious people walking around.
The situation in Europe
Figure 1 plots a group of predominantly European countries according to the number of cases (x-axis), tests (y-axis), and deaths (size of circles) during the previous seven days (May 11-18 or the latest available), everything per million inhabitants and on a logarithmic scale. The colored lines indicate different intervals for the shares of positive tests.
In each end of the spectrum we find two of the countries that did not impose strict lockdowns. In Iceland a strategy based on massive testing, contract tracing, and isolation of those infected was used to get control of the epidemic. At the time of writing, the country has only 6 active cases out of a total case count of 1,802, which is a relatively high number given the small population size (350,000 people).
At the other end, Sweden has become isolated as the only country with a stare of positive test consistently in the 10-15% range. Despite a comparatively low test activity, Sweden discovers around 400 weekly cases per million inhabitants, which is the highest in Europe, followed by the UK. But given the much lower test activity in Sweden, the actual share of infected people is likely to be much higher than in any other European country.
While Iceland has no fatalities during the last week, Swedens death count for the last seven days is the highest in Europe along with the UK.
Figure 2 shows the development in weekly tests and cases from April 1st until today. In the beginning of April, many countries lacked testing capacity and had to restrict testing to high-risk groups. The result was very high shares of positive tests.
In the UK , the share was close to 50% until mid-April. The shares of positives have fallen remarkably in most countries. In some countries, e.g. the Italy, Spain, Belgium, Ireland, and the UK, this is related to an expansion of testing. In other countries, e.g. France and the Netherlands, testing is still limited, and the lower positive shares most likely reflect a decrease in the overall infection level.
The movement toward suppression
There may be several reasons why Europeans countries are increasingly moving toward a suppression of the epidemic. At the onset of the outbreak, it was often argued that trying to stop the spread of the virus would be futile and too expensive.
However, top-economists, including Paul Romer and Larry Summers, have increasingly been emphasizing, that it is the presence of the virus rather than the social distancing policies that threatens the economy.
Google mobility data appear to confirm this suspicion. Since the start of April movement patterns have been affected very similarly across Scandinavia, despite very different policies in the three countries.