New research from the Policy Studies Institute (PSI) shows that only a quarter of English primary school children are allowed to walk to school alone – yet in Germany, three quarters are. It is easy to think that the decline in children’s freedom to play out of doors and get around on their own is an inevitable side effect of modern life. That is why international comparisons are so valuable: they can show us how things might be different.

The Germany-England comparisons are rightly grabbing the headlines; yesterday’s Sunday Times ran an exclusive news story (mostly behind its paywall) on the findings, and it was also picked up in the Daily Mail. [Update 16 Jan: it was also covered in the Telegraph and Independent.] And the figures do make striking reading. The study shows that German children enjoy consistently higher levels of independent mobility across a range of ‘licenses’ (including travelling to and from school unaccompanied, travelling by bus and by cycle) and a range of ages.

But the research has more intriguing stories to tell. For example, it finds that the independent mobility of German children has also declined in the last 20 years, like that of their English peers – but nowhere near as much. In fact, if we were to wait for the independent mobility of German primary school children to fall to the level of their English peers, we would have to wait another 60 years, on current trends.

The report makes a strong case for the importance of children’s independent mobility. It is clearly a factor in children’s physical activity levels, and hence their levels of overweight and obesity. It is also relevant to children’s health, well-being, and more fundamentally to what a good childhood looks and feels like. It is revealing that research last year from the Children’s Society found that freedom of choice was the single most significant factor in influencing children’s overall levels of subjective well-being.

The study itself has only limited insights to offer about why English children’s independent mobility has fallen so much over the last forty years, and so much more than in Germany. The Sunday Times and Daily Mail pieces take the easy option [update 16 Jan: as does the piece in the Independent] by pointing the finger of blame at English parents, with their use of the phrase ‘cotton wool kids’. My own view is that it is differences in car culture, not parenting culture, that are key – as I have argued before.

Many German cities have efficient public transport and safe, popular walking and cycling routes, along with generous, well-managed green spaces. Take for example Vauban, a new neighbourhood in the Southern German city of Freiburg, which I visited in 2005. The housing, road network and parks and open spaces are thoughtfully laid out, so that almost all homes look out on some attractive public green space. Cars are parked away from houses and apartments, while an efficient tram system means fewer families feel the need to own a car at all. The front streets are designed along ‘home zone’ lines to be sociable spaces where the car driver is a guest. It is no wonder that families are queuing up to live in the area.

The PSI report, which has in effect been four decades in the making, adds another generation of data to its seminal One False Move study published in 1990. The result is a dataset that is of unique value in researching children’s independent mobility, as I know from having been on the project’s advisory group since its inception. Not only do we now have baseline and trend data from England, together with a set of comparable baseline data from Germany. Now, for the first time, we have time trend data from both countries.

One of the PSI study’s co-authors, Mayer Hillman, deserves a special mention. A longstanding and uncompromising policy analyst and campaigner on environmental issues, it was Hillman who realised over forty years ago the significance of children as an indicator of the quality of the habitats in which they live, just like salmon in a river. His work has been a big influence on my own thinking.

The report holds back from making detailed policy recommendations, in part because a more extensive set of studies, comparing children’s independent mobility in 16 more nations, is in the pipeline. Nonetheless, its 248 pages are well worth studying in detail for their insights into the changing nature of childhood. I plan to revisit the findings, and would be interested to hear your views on their implications.