&gt;&gt; &quot;Let&#x27;s say you&#x27;re running a great country with a great economy, Singapore. And, suddenly in a gesture of humanity, you open borders, and you have 5 million people stream in, maybe ten. How good is Singapore going to be as a destination with that kind of migratory assault on resources, infrastructure, culture, economy etc?&quot;<p>Well some of the concerns you are raising here are offset by simple economics.  As more people arrive, due to fixed supply of land and limited ability to import resources, prices of everything will gradually increase, up to a point where the next potential immigrant would no longer be interested in immigrating.