In coming decades as coastal communities around the world are expected to encounter sea-level rise, the general expectation has been that people’s migration toward the coast will slow or reverse in many places. However, new research co-authored by Princeton University shows that migration to the coast could actually accelerate in some places despite sea-level change, contradicting current assumptions.

The researchers used a more complex behavioral decision-making model to look at Bangladesh, whose coastal zone is at high risk. They found job opportunities are most abundant in coastal cities across Bangladesh, attracting more people whose agricultural income opportunities decline in other parts of the country. Meanwhile, the populations already living along the coast tend to stay, as floods increase their losses but few better alternatives are present elsewhere.

Improving people’s access to financial credit is commonly proposed as a policy lever to incentivize migration away from climate hazards, but surprisingly this new model demonstrated that credit access actually increased the number of people who chose to stay along the coast. The researchers attribute this “mooring” effect to people having fewer opportunities elsewhere and being able to use credit to protect their households along the coast.