[size=0.9em]Research has shown that lower communication costs can act as a centralising force, prompting workers tend to rely more on the help of others and to specialise on a narrower set of tasks. This column reveals how reduced travel times resulting from a new high-speed rail transport in France fostered functional specialisation across different units of firms and greater centralisation. The findings highlight the mechanisms determining the level and distribution of productivity in an economy, and their redistributive impact both between and within firms