This would be interesting, except that it is pure bunk. Children may have less public physical space (and even that is debatable), but their personal space has expanded considerably, especially in the US. The flat I live in (built 1905), originally housed a family of seven, three adults and four children. It now houses three: two adults and one child. This is not uncommon. With the number of children shrinking (in Western Europe and North America) and houses getting larger, many children have their own rooms, which would have been unimaginable a century ago and probably even half a century ago, a time that Jeninks seems to idolize. While some children may have roamed freely on farms, many others were crammed into tenament buildings.

Dan makes a good point but one that is unrelated to either the original essay or John's commentary thereon. I believe the point here is that, even in cities, children had a public, outdoor space, usually shared with others, in which to negotiate with the world. In cities this included designated play areas (i.e. parks) as well as alleys, vacant lots, and streets. Jenkins' point is that such negotiated spaces have become virtualized.

Ask yourself: how many parents nowadays -- regardless where they reside -- would allow their 9 or 10 year old children to take off on a bicycle, with no plans or supervision, for an entire day? Yet my parents did, and such was typical behavior for families in the 70s.

Point is: modern parents substituted public, social free space for private bedrooms, and virtual entertainment.