One reason chose Aus was because exchange rate was US$1.20 = Aus$1. Could send home more money. 3 yrs later, nosedived to US$0.57, 'coz of the opening of the iron mine in Brazil which has hi-grade iron ore deposit enough to supply earth for 500yrs. Competiting Aus, the biggest exporter of iron ore to Russia, China, and rest of Asia.
Also, a technological breakthrough in farming lead to surplus in USA. Rather than burn their surplus wheat, etc and slaughter their cows, etc, Uncle Sam subsidized farming in the form of reduced tariff. Leading to a drop in price. Again, competiting Aus, the largest exporter of these products to Russia, China, etc.
Has never recovered. But now, creeping up. Current rate is US$1.07. One advantage of living in Aus is its resilient ability. Yet another reason for sheilas to choose Aus instead of USA. Hehehe.