
I don't think such a Canada is any more "culturally similar" to
the United States than England. In terms of laws regarding individual
rights, restrictions on police searches, etc... (all closely
related to crime) Canadian laws parallel England's and differ
greatly from those of the United States.
  

Actually, they do not have "roughly the same... urban economy", 
and extremely different ethnic composition.


However, if you account for economic and ethnic differences,
the difference disappears completely: Seattle's minorities are
predominatly poor, while Vancouver's are middle or upper class.
The rates for whites in both cities were found to be identicle,
while the rate for poor, Seattle minorities was almost three
times as great as for the well-to-do minorities of Vancouver.
The pattern seems to be one of poverty and race relations, not
one of gun control.


That is a gross distortion: "Self-defense" does not mean killing
the attacker. There were 21 cases of civilians killing their 
attacker in self-defence. But such cases represent less that
0.5% of the crimes prevented by armed self-defence; for every
case you cite, there were over 200 other cases of self-defence
where the crime was prevented but the attacker was not killed.
(0.5%, by the way, is the most conservative possible figure,
based on the National Crime Survey's estimate of 80,000
crimes prevented by armed self-defence each year. Most other 
studies on the subject put the figure at 500,000 to 600,000.
Those figures would imply less than 0.08% of sucessful self-defences
involve killing the attacker.) 

So, more correctly, there over 4000 (possibly as many as 25,000) 
cases of civilians acting in self-defence, only 21 of which resulted
in the death of the attacker. This is a significant factor, in
comparison to the 592 homicides. If memory serves, homicides
make up approximately 1% of the violent crimes the study
considered, so the fair comparison would be 40 - 250 homicides
prevented and 592 homicides. Clearly, the study can not be
close to accurate, since it ignored these cases of self-defence.