It's usually not even that they are so much worse. It's just that the monetary value differences make up the difference. These people can live a much better lif

It's usually not even that they are so much worse. It's just that the monetary value differences make up the difference. These people can live a much better life in Poland with a Denmark subsistence wage, then they can in Poland with the minimum wage. So they sacrifice some months of their lives living in worse conditions in order to make some money for back home, where they can use that money to improve the lot of their children.