Are larger cities more central in urban networks: A meta-analysis

As cities develop more and longer-range external relations, some have challenged the long-standing notion that population size indicates a city's power in its urban system. Instead, they contend that cities' centrality within urban networks provides a better indicator of power. But are city population size and city network centrality really independent properties in practice, or do larger cities tend to be more central in urban networks? To answer this question, we conducted a systematic literature search and performed meta-analysis on 36 reported correlations between city size and degree centrality. The results show that population size and degree centrality are significantly and positively correlated for cities across various urban systems (r=0.75), but the correlation varies by network scale and type. The size-centrality association is weaker for global economic and transportation networks (r = 0.43), and stronger for non-global social and communication networks (r = 0.92). The findings suggest that while city size and centrality may become decoupled at the global scale, size and centrality are closely associated at the regional and national scales, thereby clarifying seemingly contradictory predictions in the literature regarding the association between size and centrality for cities.