Did you actually look at information for either of the countries that you cited? Immigrants make up 20% of Switzerland's population. (https://en.wikipedia.org/wiki/Immigration_to_Switzerland). Japan's economy has been struggling for years now (http://www.wsj.com/articles/why-japans-economy-is-laboring-1...), and their population is aging at a rapid rate, compounding the economic stagnation, something immigration helps to combat (http://qz.com/173379/immigration-is-saving-the-us-from-an-ag...).