Roads, rails, and checkpoints: Assessing the permeability of nation-state borders worldwide

•A novel border permeability dataset is created, covering 312 land borders globally.•More (and better) cross-border transport infrastructure and fewer checkpoints lead to higher border permeability.•Europe and Western and Eastern Africa have the most permeable and the Americas the least permeable borders worldwide.•Economic development is by far the most relevant explanatory factor of border permeability.•Borders of rich and poor countries are highly permeable, but those of moderately prosperous countries are harder to cross.