By Bryan Mezue
An important debate in our class has centered on the relative benefits of building new cities up from the ground up versus retrofitting old cities for growth. It is clear that we have no choice but to do one of the above to accommodate for the great urbanization trend, especially in the developing world. I do not think one model is always right. Instead, this blog post seeks to propose a theory of decision-making to support a choice between the models. I believe the choice should come down to an assessment of three key factors.
Capacity. Fundamentally, cities are built (or rebuilt) to house people. One of the main considerations should be the expected population increase, and thus the required living capacity increase. Many existing cities have capacity constraints and simply cannot grow fast enough to match immigration. However, in other cases, there is plenty of space for an organically growing city to absorb an immigration influx. This is especially true in many developed countries where the rate of rural-urban immigration is stabilized. In the case of King Abdullah Economic City (KAEC), it is arguable that existing Saudi Arabian cities probably had enough capacity to absorb new growth, and thus capacity should not have been a justification for the construction of the new city.
Integrability. Cities do not exist in isolation. One of the most important drivers for a city’s success is how integrated it is with other cities, transport and communications infrastructure and with natural resources. Most ancient world cities – and many of today’s largest cities – were initially built around these features and grew organically to absorb other features. When choosing to build a new city (versus expanding an existing successful city), an important consideration is whether the proposed site is integrable with existing features (and predicted features). The type of integration is often also a strong influencer on the culture of the new city – as an illustration, a new city integrated primarily around a natural resource (e.g. coal) will likely become a ‘resource city’ (e.g. a coal-mining city). This factor is often one of the least understood when building out a new city. If the decision maker cannot ascertain that there is enough integrability (from the perspective of the expected demand capacity), then the default should be to fall back on an expansion project. In the KAEC project there is some integration around resources (e.g. port), but the level of integration with infrastructure and existing cities is questionable.
Innovation. A final consideration is a city’s ability to absorb new technology. In some cases, the technology shift requirements may be too high for an existing city, and it is rational to build a brand new city. This can be adequate rationale for choosing a new city, assuming that the capacity demand and integrability issues are also addressed. In such an event, a new city is likely to succeed, especially if this new technology can foster new employment.
Decision-makers should put on a customer-focused mindset and consider competition from other cities when they consider a build vs. expand choice. Incoming dwellers ultimately choose a city that is well-integrated, has affordable capacity and satisfies employment needs.