Mid‑decade estimates show immigration long offset domestic outflow; recent fall in arrivals may slow growth

Susan Strait, senior manager for the Population Estimates Program at the UMass Donahue Institute, told the Senate Committee on the Census that international immigration has been the dominant force offsetting net domestic out‑migration in Massachusetts and driving much of the state’s recent population change.

Strait said Massachusetts’ growth rate from 2010 to 2020 was roughly 7.4 percent, similar to the national average, and that a recent rebound in net international migration peaked in 2024, with UMDI’s estimates approaching about 70,000–78,000 net international migrants that year. She cautioned, however, that 2025 shows a marked decline and that future data will likely reflect continued reductions linked to federal policy and administrative changes. “Immigration has always offset that net domestic out migration,” Strait summarized.

The presentation highlighted two planning‑relevant patterns: immigrants are concentrated in prime workforce ages (roughly 20–49), and foreign‑born Massachusetts residents are bimodal in educational attainment—higher shares with graduate degrees and higher shares with less than a high‑school diploma—affecting workforce composition. Strait used American Community Survey flow data to show common state trading partners (New York, Rhode Island, Florida, California, New Hampshire) and stressed that young adults (18–24) show strong in‑migration while the 25–34 group commonly shows net out‑migration.

Committee members pressed on measurement issues. Strait explained that people who first move into group quarters—dormitories or similar settings—may not appear as in‑migrants until they enter household populations, a nuance that can mask short‑term inflows tied to college populations. Senator Liz Miranda raised the related question of incarcerated people and representation: Strait reiterated Census Bureau practice counts residents where the facility is located (group quarters), not in their home communities, and noted that some advocacy groups have pushed for alternate treatments.

Strait also reviewed the vintage timing of the projections and scheduled data releases: county components in March, city and town level estimates in May, and age/race breakdowns in June. She repeatedly emphasized that migration assumptions largely drive near‑term projections and that the drop in international migration observed in 2025 would bend down several of the scenarios used by state planners.

The committee closed the exchange by noting these mid‑year estimates and vintages will be crucial to updating housing and labor‑force planning.