But: why would the EU and US be the appropriate geographical units to organise self-sufficiency for, instead of Luxembourg and Rhode Island?

An excellent question. The only reason I picked the US and the EU (and had to cheat with Canada anyway), is because these areas have defined themselves as coherent regions.

What this implies is that if these regions can't be self-sufficient than they probably should not be unified political entities either.

This is one of the reasons the EU is having so much trouble defining its membership.

If Mexico was part of a "North American Union" the economic picture would look a lot different. Think of the problems when East Germany was reunited with West Germany. Immigration issues would be replaced by poverty issues.

It just shows how much of what we take for granted is based upon lies or false assumptions.

Policies not Politics
---- Daily Landscape