Size

As cities grow, an increased population has both positive and negative effects on quality of life. The most important effects are reviewed below.

The Economic Rationale of Cities

The primary purpose of a city is to facilitate the exchange of goods, services, and information ¹. A city is typically defined as an urban area through which people can commute on a daily basis. Larger cities tend to create more wealth by offering wider job markets, labor pools, and diversity of products for sale.

Sources: ², ³, ⁴ See also, ⁵, ⁶, ⁷.

Dense cities, and the amenities they support, foster collaboration ⁸, ⁹, with results in, for instance, more patents ¹⁰.

Due to this agglomeration effect, there is a tendency for population growth to concentrate in existing cities rather than new cities. There should be other factors to motivate the construction of new cities, particularly in an exotic location that is far from existing cities.

Cities and Transportation

Cities fit into the larger national and world economies, and consequently they need to exchange goods, services, information, and people beyond their borders to thrive. There is extensive evidence (for example, ¹¹) that access to intercity transportation is a major factor in city success.

Better transportation, together with telecommunications, have been found to help foster academic collaboration ¹² and joint patenting ¹³. The advancement of telecommunications in particular has been important ¹⁴.

Drawbacks of Big Cities

To reap the environmental and economic benefits that come with density, it is necessary to mitigate the drawbacks. Larger and denser cities tend to have higher traffic congestion ¹⁵, crime ¹⁶, and infectious disease ¹⁷. Light pollution, noise pollution, and the urban heat island effect are challenges that grow with density; see our analyses of these topics and proposals to mitigate them.