THE MIGRATION SYSTEM INHERITED BY THE MERGED HO CHI MINH CITY: EVIDENCE FROM THE 2009 AND 2019 CENSUSES

Tóm tắt

The 2025 administrative merger of Ho Chi Minh City with Binh Duong and Ba Ria - Vung Tau created a single administrative unit of approximately 14 million residents, raising the question of how far the three territories already functioned as an integrated migration system. That question has not been examined with migration data at a sub-provincial spatial scale. This study measures the spatial structure of inter-district migration across the merged city over the two observation windows 2004-2009 and 2014-2019, using the microdata samples of the 2009 and 2019 population and housing censuses, with sample densities of 15.0 and 8.5 percent of households, respectively, distributed through the Integrated Public Use Microdata Series. The analysis covers 38 districts grouped into 13 functional regions and applies system-level measures of migration intensity, connectivity, effectiveness and spatial concentration. Because district-level information on previous residence is incomplete in the 2009 sample for inter-provincial migrants, the analysis uses three comparable analytical layers. Four findings emerge. Migration intensity declined by 44.7 percent between the two windows, from 6.12 to 3.38 percent of the population aged five and over. The network became sparser rather than more concentrated, since connectivity fell from 98.3 to 94.0 percent while measures of concentration did not change. A subsampling test confirms that this thinning exceeds what the smaller 2019 sample alone would produce, although the 35 lost links carried only 0.34 percent of total volume, so the system shrank without restructuring. Migration shifted upward through the spatial hierarchy, with the share of flows crossing former provincial boundaries rising from 12.4 to 15.5 percent, because cross-boundary flows fell by only 4.5 percent while short-range flows fell by 27 percent. Finally, the geography of population redistribution moved outward, and three functional regions reversed their roles between sending and receiving. The results are consistent with functional integration that preceded the administrative reform, while showing that the merged territory operates as several distinct sub-systems rather than as a single homogeneous migration system.