Our City Observatory report, Less in Common, catalogs the ways that we as a nation have been growing increasingly separated from one another.  Changes in technology, the economy and society have all coalesced to create more fragmentation and division.

As Robert Putnam described this trend in his 2000 book, we are “Bowling Alone.”  And while work, housing and shopping have become more stratified and dispersed, there still ought to be the opportunity for us to play together. Sports fandom is one of the few countervailing trends: within metropolitan areas popular support for the “home team” whether in pro-sports or college athletics is cuts across demographic and geographic boundaries.

But in our personal lives our recreation is becoming more isolated, chiefly through the privatization of leisure.

Consider:  instead of going to public parks and playgrounds, more children play in the copious backyards of suburban homes. This trend is amplified by helicopter parents.  Free range children are an anomaly, and the combination of sprawl and insecurity adds to the chauffering burden of adults–which in turn means spending more time in cocooned private vehicles. And as we know, the decline in physical exercise among the nations children has been a key factor in the explosive growth of juvenile obesity.

One of the hallmarks of the decline in the public recreational commons is swimming.  In the early part of the 20th century, swimming pools were almost exclusively in the public domain.  Prior to World War II it was estimated that there were fewer than 2,500 homes with private, in-ground swimming pools.  Today, there are more than 5 million.

That’s one of the reasons we found Samsung’s television commercial “A Perfect Day” so compelling. It highlighted the adventures of a group of kids, cycling around New York City, and ending up spending time at a public pool.  Its encouraging that a private company can make our aspirations for living life in public a central part of its marketing message.

That’s certainly a contrast to the trend of commoditization of leisure. Increasingly, we pay to play, and play in the private realm.  The number of persons who belong to private gyms has increased from about 13 million in 1981 to more than 50 million today.  While gyms provide a great experience for those who join, they tend to draw disproportionately from wealthier and younger demographic groups–again contributing to our self-segregation by common background and interest.

Over just the past five years, the number of Americans classified as “physically inactive”–not participating in sports, recreation or exercise, has increased from 75 million to 83 million, according to the Physical Activity Council.  And youth participation in the most common team sports — soccer, basketball, football and baseball — has declined 4 percent since 2008.

As we think about ways to strengthen and restore the civic commons, we will probably want to place special emphasis on parks and recreation.  Public parks are one of the places where people of different races, ethnicities and incomes can come together and share experiences.