I'm slowly making my way through Directions 2031, according to that employment self sufficiency in Mandurah is ~60-70% (can't remember exactly) which compares relatively well to say, Armadale (40%ish?). I know the unemployment rate there is currently higher than Perth but overall I'm liking what I'm reading regarding future plans for the area.
I guess that Mandurah residents are travelling out of the area to work as there is little to no employment there.
Whereas Armadale is, on the whole, lower socio economic, which may account for the figures.
All the same, I like the look of Mandurah, and I wouldn't mind retiring there which is a bonus if I had properties in this location.