Labour mobility within a large city or metropolitan area is a necessary condition for the optimal exploitation of agglomeration economies. We propose a method to establish which municipalities should be considered part of a metropolitan area based on labour market integration. In order to aggregate geographically proximate urban municipalities, we develop a network-based model that makes industry productivity (manifesting in formal employment creation) dependent on firms’ ability to find, within city limits, the diversity of skills they need to move to new complex industries. In this way, we uncover the natural city scale at which firms optimally exploit the range of skills available to them within a broad catchment area. Considering Colombian cities, we find that commuting times between 45 and 75 min, corresponding to between 43 and 62 distinct cities or integrated labour markets, allow firms to maximise formal employment creation (between 2008 and 2013). This result supports the development of passenger transport limiting commuting times within cities, connecting small- and mid-size cities to nearby large cities, and coordinating transportation investments across traditional administrative boundaries.

中文翻译：

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新兴城市的通勤时间和技能动员

大城市或大都市地区的劳动力流动是集聚经济最佳利用的必要条件。我们提出了一种基于劳动力市场整合的方法来确定哪些城市应被视为大都市区的一部分。为了汇总地理位置最接近的城市，我们开发了一个基于网络的模型，该模型使行业生产率（体现在正式的就业机会中）取决于公司在城市范围内寻找迁移到新的综合体所需的技能多样性的能力。行业。通过这种方式，我们发现了自然的城市规模，在该范围内，企业可以在广阔的集水区中最佳地利用其可用的技能范围。考虑到哥伦比亚的城市，我们发现通勤时间介于45至75分钟之间，对应于43至62个不同的城市或综合劳动力市场，使企业能够最大程度地创造正式就业机会（2008年至2013年之间）。这一结果支持了客运交通的发展，限制了城市内的通勤时间，将中小城市连接到附近的大城市，并协调了传统行政区域内的交通投资。