The emergence in the United States of large-scale “megaregions” centered on major metropolitan areas is a phenomenon often taken for granted in both scholarly studies and popular accounts of contemporary economic geography. This paper uses a data set of more than 4,000,000 commuter flows as the basis for an empirical approach to the identification of such megaregions. We compare a method which uses a visual heuristic for understanding areal aggregation to a method which uses a computational partitioning algorithm, and we reflect upon the strengths and limitations of both. We discuss how choices about input parameters and scale of analysis can lead to different results, and stress the importance of comparing computational results with “common sense” interpretations of geographic coherence. The results provide a new perspective on the functional economic geography of the United States from a megaregion perspective, and shed light on the old geographic problem of the division of space into areal units.

Whether to treat regions as distinct, bordered entities or meshes of borderless flows has long been a debate for geographers. This paper uses the methodological and conceptual insights of network analysis to argue for an approach to regionalisation that treats them neither as perfectly enclosed nor perfectly borderless. By comparing the many contested readings of ‘community’ in geography and the social sciences to the operational definition of a ‘community’ in graph theory, I extend historic questions about the spatial definition of human communities and describe how network analysis can offer insight about the texture of human geography. A case study, using network data about commuting in the New England region of the US, shows how these algorithmically‐detected regions are both stable and fluid at once. The paper proposes the term ‘conchoration’ to describe the ontology of emergent, functionally whole regions which are nevertheless perforated and interdependent.

This paper examines the use of the metaphorical terms ‘mosaic’ and ‘tapestry’ in conceptualizing the structure of spatial organization over more than a century of geographic thought. The duality between a mosaic-like, discrete geography and a tapestry-like, indiscrete geography is one of the fundamental paradoxes in spatial ontology; this paper explores how this duality has configured the commitments of geography and continues to play a role in the more recent debate between ‘territorial’ and ‘relational’ spatial metaphors. It argues for a reconciliation of incompatible metaphors, since the complexity of the phenomenal world exceeds resolution into any single descriptive system.

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