alt Hacker NewsSure, take that stricter immigration control. But if people assume upfront that immigrants are intrinsically the source of problems and it takes stricter and stricter controls to filter them down to only those that bring value, this strengthening of filtering will never end.
Remember that one does not _either_ bring value or cause problems. I expect a typical human being to bring some value and cause some problems at the same time. And you can never measure which one is bigger.
I never said that all immigrants are intrinsically a source of problems, and saying that any filtering inevitably leads to never-endingly stronger filters is a slippery slope fallacy.
You absolutely can measure the likely degree of problems an immigrant would bring. To an absurd, extreme, example: you have 1 spot open for immigration. Do you offer it to a semiconductor EE with a clean criminal record in his early 30s, or a 68 year old alcoholic high school dropout with multiple violent criminal convictions?
It's relatively easy to design a system that prioritizes skilled, contributory immigration: academic background, professional career, salary, age, ability to speak the host country's language, skills of relevance, health/fitness, etc.
Sure, the EE from my example can snap and commit a crime, or lose his job and get addicted to drugs; but at a population level, it's inarguable that some groups will cost a country and others will benefit a country.