Deepening Megaregional Interrelatedness Through Migration: The Case of the Northern California Megaregion

The increasing connectedness between neighboring metropolitan areas anchored by global economic centers highlights the relevance of the megaregional scale for government and governance. Yet, there is a lack of data to examine the expansion of megaregions and understand prevalent challenges to coordination. We use data from the Census Bureau and the California Franchise Tax Board (FTB) to analyze migration patterns within the Northern California Megaregion that combines the San Francisco Bay Area and California Central Valley and highlight different trends underlying regional expansion. We find that people are leaving Bay Area zip codes at the edge of the urbanized area where population growth is robust, migration rates lower, job accessibility is low, rents are nearly as high as the more central locations, and home values are lower, making it difficult to move elsewhere within the Bay Area. Moves into the Central Valley are divided between the suburbs of the main urban centers and isolated towns leading to fragmented growth that increases stress on transportation infrastructure and worsens spatial inequality in the region.