a. please define 'a failing economy'
b. please provide examples of failing countries that were rescued by immigration : Lebanon ? no, its christian majority became a persecuted minority. Norway ? no, but a very wealthy country. Haiti ? no, and very poor. Sweden ? not on your nelly.
The pattern is this : a. The wealth happens and then b. The immigration happens. That is why there is so little immigration into the poorer parts of Eastern Europe. And a ton of immigration into wealthy London, France, Luxembourg.