The connection between density and environmental sustainability appears less and less ambiguous — high-density urban dwellers consume fewer scarce resources, produce less waste, and occupy far less space than other individuals on a per capita basis. Even those who recognise the limits of denser development, that we can't create ultra-efficient "Manhattans" in every corner of a country, or those that advocate for a plausible Goldilocks density acknowledge the massive scale benefits of denser urban design.
Whether urban planners and developers pursue a Manhattanisation of American cities or more modest TOD (transit-oriented development) growth patterns, the demand for denser urban habitats is clearly on the rise. The relationship between density and sustainability, however, raises another question concerning the potential benefis of denser planning: how does density impact our civic and political behaviour? If increased density promotes socioeconomic opportunities, environmental sustainability, and reductions in waste, what does it do for our social and political lives?
The city and civic decline
Writing at the close of the 20th century, prolific Harvard political scientist Robert Putnam's book Bowling Alone offers perhaps the most lucid and compelling account of the decline in civic engagement in the US. Chapter 12, "Mobility and sprawl", focuses upon the simultaneous and ongoing increases in mobility (frequency of movement) and sprawl (suburbanisation). Putnam concludes that "getting involved in community affairs is more inviting — or absention less attractive — when the scale of everyday life is smaller and more intimate", with statistics illustrating that "metropolitans are less engaged because of where they are, not why they are [ … ] living in a major metropolitan agglomeration [ … ] weakens civic engagement and social capital." Rather than promoting access to and opportunities for political and civic involvement, cities seemingly promote alienation, disengagement and diminished social capital.
Certainly Putnam's findings should give urban planners and private developers pause — as we expand and grow our cities, are we inexorably diminishing good citizenship? The short answer is "not necessarily". Bowling Alone considered only absolute measures of a city's population rather than density. A closer look at density and civic engagement may yield additional insights.
The idiosyncratic city?
Recent data released by the US Federal Agency for Service and Volunteering, the Corporation for National and Community Service (CNCS) and the National Conference on Citizenship (NCoC) tell an interesting if counterintuitive story. In a survey of America's largest cities, the five highest-rated cities — those with the highest participation in volunteering activities, neighbourhood events, civic organisations, and with general interest in and knowledge of politics, among other factors — are a variegated bunch. At one extreme, Minneapolis, Rochester NY and Seattle present a challenge to the "urban anomie" phenomenon described by Putnam. All three have population densities in excess of 6,000 inhabitants per sq mile (2,316 sq km). At the other extreme, Salt Lake City and Jacksonville have population densities under 2,000 per sq mile (769 per sq km). For comparison, Greater London's is around 13,500 per sq mile (5,200 per sq km) while Paris' is 55,000 per sq mile (21,000 per sq km).
Data on America's densest major cities add further complkications. The five densest cities include New York City, San Francisco, Boston, Chicago and Philadelphia. New York City, with more than eight million inhabitants and a density well over 20,000 per sq mile, ranks near the absolute bottom of all cities in volunteering and civic participation rates: 49th of the top 51 major metropolitan areas, and consistently below the US national average. In fact, of America's five densest cities, only one ranks among the top 25: San Francisco.
One of several large cities anchoring the Bay Area of northern California, San Francisco is America's second most densely populated major city (17,200 per sq mile) and is rnaked eighth for volunteering and civic participation. Nearly one in three San Franciscans reported volunteering within the last year, clocking in more than 90m combined volunteer hours and $2.5bn in contributed services. With an affluent population, low unemployment and numerous leading research universities nearby, San Francisco presents a challenge: is the density-civic engagement relationship idiosyncratic, or are there generalisable patterns of evidence to inform our planners and developers?
Learning from sustainable, engaged civic leaders
Of the countless factors that promote or constrain opportunities for civic engagement, two merit additional specific attention: education and religion. Educational and religious organisations, when combined, account for more than half of all volunteering in the cities profiled in the NCoC/CNCS data.
Seattle and San Francisco, for instance, both contain several major universities in their metropolitan regions, have well educated workforces and strong employment figures. For each of these west coast cities, educational organisations account for the largest shares of volunteers, perhaps also benefiting from the relatively close proximity of their universities to denser urban cores and mass transit routes. Salt Lake City and Jacksonville, two of the nation's most religious metropolitan areas, have substantially more volunteers participating through religious organisations.
Notably, Salt Lake City is the centre of the Church of Jesus Christ of Latter Day Saints, more commonly known as the Mormon Church. It is the only major American city surveyed with more than half of its volunteering occurring through religious organisations, though several southern and Great Plains cities rank very highly on this metric as well.
Clearly the melange of confounding, counterintuitive evidence presents a challenge to urban planners. As our cities increasingly focus on sustainability, social connectivity and economic opportunity, the consequences of planning for political and civic engagement remain uncertain. Nevertheless those cities that set the standards for sustainability, transit planning and engagement — such as Minneapolis-St Paul, Seattle and San Francisco — offer guidance to cities elsewhere in the US and globally. In the pursuit of greater environmental, socioeconomic and political opportunities, cities should pursue a thorough stocktaking of their educational and religious institutional resources, leveraging those often-overlooked assets through subsequent partnerships and mobilisation programmes.