Interesting....I assume you are aware that high immigration has been around for more than a century.  The homeless issue is certainly one requiring more attention but it's a stretch to link it to high immigration rates.  Mental illness and training are more likely causes.  Want to see an example of what happens to the economy  when immigration is low?  Take a look at Japan and their ageing population.  Who is going to provide tax revenue to support them as they continue to age?