A nation is a group of people and a state is the political and diplomatic fiction that rules that nation. You should make a strong distinction between the two and acknowledge that the nation is what has caused Germany to be so productive. Germany is not prosperous and powerful because it has a good state - it has a good state and is prosperous and powerful because it has the right nation. The Germans are a naturally productive nation. If you were to switch the population of Germany with that of Somalia, you would find that Somalia would become prosperous and powerful and Germany would collapse in a matter of weeks. I think you should step away from the purely economic argument and look at it from a more cultural perspective. Some cultures build, other cultures destroy. Some cultures encourage productivity and security of property, other cultures encourage lethargy and theft. Mass immigration, especially from outside Europe, will only hurt Europe tremendously in the long run.