Ed Glaeser, Giacomo Ponzetto, and Yimei Zou recently published a new academic paper called, Urban Networks: Spreading the Flow of Goods, People and Ideas.
The paper looks at whether it’s more advantageous to build huge and consolidated mega-cities or build connected networks of smaller urban centers (perhaps connected by high speed rail). As countries like China rapidly urbanize, this is something that many people are thinking about.
In China, there is a lively urban planning debate about whether to facilitate the increased expansion of the vast agglomerations of Beijing and Shanghai or whether to focus on creating networks of cities that are smaller, albeit still much larger than almost all of the cities of Western Europe. The current government policy favors networks, in the hope that connected smaller cities may be free of the extreme downsides of mass agglomeration, such as extreme congestion, pollution and high housing costs.
Like most things, there are real trade-offs.
In the paper, they assume that larger cities lead to more urban amenities, which in turn serves as an important magnet for skilled workers. However, for unskilled workers who may not care/benefit from the same urban amenities, it is possible for them to dislike the bigger cities. In this case, the benefits do not outweigh the negatives of urban expansion and an urban divide is created (rich/poor).