My point was that the US economy is better than all three of your examples so using them as an example of how awesome an economy you can have with a high minimum wage is pretty silly.
Also, adjusting for currencies, I get the following
Minimum Wage in New Zealand: $7.35 US
Minimum Wage in Canada: $9.00 US
Minimum Wage Australia: $13.34 US
Cost of Living Adjustment:
Effective minimum Wage in New Zealand: $6.02
Effective Minimum Wage in Canada: $8.42
Effective Minimum wage in Australia: $10.27
So only Australia has a significantly higher minimum wage, but that wage only applies to adults, and I would like to see how many "adults" do menial labor in Australia.