Abstract
I investigate how the housing market in a binational agglomeration responds to a large trans-border public transport connectivity improvement. For this, I exploit the recent introduction of the Léman Express, a suburban train service in the Greater Geneva area. The new line seamlessly connects the Swiss and the French side of the agglomeration, resulting in a substantial travel time reduction. I document locally concentrated construction booms and increasing prices at locations benefiting from the new service about two years in anticipation of the opening. I study the impact of the anticipated commuting cost decrease on residential mobility flows and discuss the resulting changes in neighborhood composition. Locations near soon well-connected stations experience a shift towards affluent, home-owning cross-border workers resulting in a gentrification push for these historically predominantly poor neighborhoods. This is largely driven by inflows from adjacent areas and internal relocations whereas trans-border relocation flows remain unimportant.