This is not difficult, looking at the kind of migration e.g. Germany has in the millions. When taking averages and means of migrant KPI over the migrant populat

This is not difficult, looking at the kind of migration e.g. Germany has in the millions. When taking averages and means of migrant KPI over the migrant population at large, any good will be cancelled out by the negative aspects of 3rd world pauper migration. Because the subpopulations are vastly differently sized. Any 1st world country with more tightly controlled migration should do better.