Many cities now striving to manage growth will soon be trying to reverse population losses or struggling to thrive despite depopulation. There are so many unknowns that some cities have difficulty predicting which way they are headed. In this age of uncertainty, it may make sense to plan for multiple potential futures. By seriously considering the distinct possibility of population decline, cities might be able to avoid the doom loops that vex many shrinking cities. Spoiler alert: doom loops are bad for nature as well as humans.
Doom Loops
The germ of a doom loop can begin when a city, county, or region develops a plan for one future, often after acknowledging that many different futures are possible. For example, there might be a wide spectrum of projections ranging from population boom (often labeled the “optimistic” projection) to bust (often labeled the “pessimistic” projection). But instead of exploring both ends of that spectrum, the plan is often built primarily on the so-called “likely projection” which conveniently sits in the middle of the range.
By underestimating actual population growth pressure, the plan might inadvertently constrain growth and/or create deficiencies in schools, emergency services, and other public infrastructure.
But if the plan overestimates actual population growth, the outcomes are arguably worse. By overestimating future population, a plan might open an inordinately large part of its countryside to development by expanding urban growth boundaries, rezoning these extensions for urban development, and serving the new growth with roads, sewers, water mains, schools, fire stations, parks, and other infrastructure.
If the growth spurt ends, (or worse, if population subsequently shrinks), the city ends up with abandoned houses that will have to be demolished at public expense if they become a public nuisance. Shrinking cities like Detroit, Michigan and Youngstown, Ohio typically are unable to completely convert depopulating neighborhoods because some residents resist moving even when offered generous relocation incentives.
Even unoccupied houses often remain vacant because their owners refuse to sell and continue to pay taxes on their abandoned properties. As a result, shrinking cities continue to provide public services to these neighborhoods at an increased cost per house while the number of taxpaying households is shrinking. As the city’s fiscal health declines, it may be forced to reduce the level of public services. This makes failing neighborhoods increasingly undesirable, prompting even more departures by those households that are in a position to flee. In addition to being catastrophic for the human environment, doom loops represent the unnecessary waste of land that should have been retained as farmland, habitat, watershed protection, or any of a number of other rural land uses.
The Uncertainties
For its first 249 years, the United States has seen steady population growth. So far, shrinking cities could at least hope to capture some of the country’s overall population increase.
But US birthrates are falling. The 1960 fertility rate of over three births per woman fell to 1.66 births per woman in 2020. Demographers seem to agree that the US may never return to the full replacement rate of 2.1 births per woman.
A largely welcoming immigration policy has so far offset our falling birthrates. However, the current US administration pledges to reduce immigration. This combination of lower birthrates and reduced immigration means that US total population will peak and begin to decline at some point in this century – perhaps as soon as a few decades from now.
Cities are also facing the potential for workforce reductions caused by economic decline, chaotic tariff policies, and the real threat that artificial intelligence is on course to replace millions of human workers. As I write this item in April 2025, many economists are forecasting that the US will be in recession by the end of the year.
Some cities were able to attract remote workers during the COVID pandemic and its aftermath. But many employers are now requiring a return to the workplace, making the Zoomtown approach to economic development an increasingly risky proposition.
Furthermore, climate change is upending the assumption that wildfires, floods, water shortages, severe storms, and dangerous heat events will happen somewhere else. In response, the new leadership in Washington, DC seems determined to remove the federal safety net that previously provided assurances that a city could bounce back from a disaster. For example, the current federal administration is threatening to abolish the Federal Emergency Management Agency (FEMA) which until now could be relied on to help cities recover from catastrophic events.
Adaptive Planning
Planning for more than one future would be less necessary if the future was more certain or if the planning process was fast enough to keep pace with changing circumstances. The typical comprehensive plan for US cities takes from five to seven years from launch to adoption. Obviously, a city can go quite far in the wrong direction during that length of time. This is one of the many reasons why cities are now urged to prepare plans that can provide guidance despite the many unknowns listed above. In Scenario Planning for Cities and Regions, Robert Goodspeed illustrates benefits of planning for multiple potential futures with a tale of two cities: Dresden, Germany and Gwinnett County, Georgia.
Dresden’s plan for 1990 to 2000 assumed robust growth after German reunification, which prompted substantial growth at the city’s periphery. But Dresden wound up losing 60,000 people by 1995, causing high vacancy rates and abandoned industrial sites. In the five-year period from 1995 to 2000, Dresden assumed permanent decline and demolished almost 6,000 housing units. Then from 2002 to 2008, people returned to historic neighborhoods and the city was attracted new industries. The only constant during this period was unforeseeable change and it led Dresden to adopt counterproductive strategies.
In 2006, planners in Gwinnett County, Georgia dealt with uncertainty by exploring four different scenarios during its comprehensive plan update. Planners there were able to use insights from the slow-growth scenario to respond to the sudden drop in growth caused by the Great Recession which began in 2008.
Scenario planning is becoming more common as a way of exploring alternative futures. However, most cities continue to adopt comprehensive plans with just one set of visions, policies, and regulations based on a single preferred scenario. If the preferred scenario fails to materialize, the consideration of other scenarios during the planning process is undoubtedly helpful in dealing with the need to change. But it does not alter the fact that the city has an adopted comprehensive plan that no longer reflects reality.
Academics are proposing ways to move beyond scenario plans to adaptive plans that incorporate actionable policies and strategies that can be quickly used to respond to changing conditions. Unfortunately, there are few examples available to illustrate how that can work in practice. But the need for adaptive planning is clear. The future is increasingly uncertain. Without the ability to quickly adapt to change, we will end up with problems for the natural as well as human environment.
Notes
Goodspeed, Robert. 2020. Scenario Planning for Cities and Regions: Managing and Envisioning Uncertain Futures. Cambridge: Lincoln Institute of Land Policy.
Machiels, Thomas, and R. Goodspeed, T. Compernolle, and T. Coppens. Creating Flexible Plans for an Uncertain Future: From Exploratory Scenarios to Adaptive Plans With Real Options. Journal of the American Planning Association. June 2023.
