Northern Ireland v. Republic Of Ireland

The two sovereignties on the island of Ireland are very well sorted already.

one statistic stands out from a census comparison from the first decade of the twenty-first century. Just 2.1 percent of the population in Northern Ireland were born in the South, and just 1.3 percent living in the South were born in the North.

And that is with rights of free migration.

Via Marginal Revolution.