Second Report: Mobility on the rise

In our first report from April 5th, we found a clear decline of mobility in Germany, leveling out at a level of around -39% less mobility compared to normal.

Since then, many people started calling for a relaxation of the current mobility restrictions, as the number of new cases in Germany dropped. Experts discuss exit strategies, and it seems that people are eager to return to normalcy.

We've been monitoring mobility closely since our last report. Did people stay disciplined and mobility at the low level? Or do we see an increase in mobility?

General mobility trends

In our updated figure for the general mobility in Germany, we see that mobility started to slowly increase since the end of March. There is a lot of variation, but the general trend seems clear: Mobility is on the rise.

We clearly see the trend when looking at the mobility for full weeks. The week with the lowest mobility was from March 23rd to March 29th, when mobility dropped to -39% below average.

In April, mobility has been slowly rising. The most recent week (April 6th to 12th) shows a mobility of -27% below the baseline. Note that the Friday of April 10th was a public holiday in Germany (Karfreitag) and thus has unusually low mobility. We excluded it in the calculation of the average mobility over the week. If we include it, mobility in the week is at -32% below normal.

An interesting feature we observed is a difference in mobility on weekends compared to weekdays: During most of March, the mobility reduction on weekends was stronger than on surrounding weekdays.

A plausible explanation for the stronger reduction on weekends is that on weekends more optional trips are taken (for leisure, travel), which were the first ones to be cut. Or, people might move trips to during the week, for example grocery shopping, to avoid getting into contact with others. Both reasons imply that on weekends trips decrease more strongly than on weekdays.

However, since the weekend of April 4th to 5th, this is no longer true: weekends are now similar to weekdays in their reduction of mobility. This reversal might indicate that people are taking up more “optional” trips again, relaxing their own restrictions. It seems that the mobility reduction on weekends is an important indicator for self-imposed restrictions of mobility.

Risk perception and mobility

What causes the recent rise in mobility? One indicator we found is that risk perception might play a role in this. If people think Covid-19 is less of a threat, they might relax their self-imposed mobility restrictions.

We compare the mobility to findings from the COSMO survey, which monitors the risk perception of Covid-19 in Germany on a weekly basis.

We find a stark correlation between the change in mobility in Germany and the agreement with statements such as “I think the current measures are too strict” (r=0.95, p<0.01). As people worry less about the dangers of Covid-19, mobility increases. This has important implications, for example on how risk should be communicated by public institutions, and will be further analysed.

Correlation to case numbers

Another connection we found is that mobility reduction is tied to local case numbers. The more cases of Covid-19 we observe in region, the stronger the reduction in mobility. In the following, we compare mobility reduction for the week of March 23-29 with all cases up to March 29th.

We find a correlation between mobility and case numbers on all spatial levels we observed: On the level of counties (NUTS 3), districts (NUTS 2) and states (NUTS 1). On the level of districts, the Pearson correlation is -0.56 (p=0.0002).

The stronger mobility reduction in areas with high case numbers can have multiple reasons. One likely reason are local differences in laws on mobility restriction, for example the stricter curfew in Bavaria. However, most guidelines are uniform across Germany and implemented in similar ways, such that this can only be a partial explanation.

Another likely factor is the local, personal perception of Covid-19: The more cases there are in an area, the more do people perceive Covid-19 as a threat, and the more they restrict their own mobility. This explanation is supported by our findings on the connection between mobility reduction and risk perception.

Summary & Outlook

Mobility in Germany is slowly increasing. From the low plateau of -39% less mobility than normal at the end of March, mobility has been rising to around -27% below normal.

Our findings indicate that the recent increase in mobility can be attributed a decline in self-imposed mobility restrictions - people are getting more relaxed, and undertake more trips they previously avoided. Possible causes are a decrease in perceived risk, paired with a decrease in case numbers of Covid-19.

In the coming weeks, we expect the gradual implementation of policies that lift the current restrictions. It will be interesting to see how different policies affect mobility in different ways.

We will further monitor how mobility in Germany develops. Stay tuned!