Why do metropolitan and administrative boundaries differ?
A metropolitan area is a functional region containing a central city and surrounding settlements integrated through commuting and services.
Formation process and geographic mechanism
Municipal borders are legal, while housing and labor markets cross them. Suburban residents work centrally, shop across districts and use shared transport. Functional areas are therefore defined using density and commuting flows. Multiple municipalities may form one economic urban system.
Spatial outcomes, measurement and management
Boundary mismatch complicates transport, air quality, housing and infrastructure coordination. A core city may bear service costs while taxes accrue elsewhere, or vice versa. Metropolitan governance may use joint plans, revenue sharing or regional bodies. Municipal and metropolitan populations should not be confused in comparisons.