Hey! I got a very similar question (in a short answer however) in my last exam so I may as well throw in my 2 cents worth

Effects of a high CAD on the Australian economy:
○ More reliance on overseas investment - becomes unsustainable to repay. Foreign debt may be solved by servicing it with overseas investment --> more outflows on the NPY account --> high/worsening CAD
○ The above can reduce the credit rating from AAA
○ May suddenly deter FDI, investor confidence & speculation as returns are no longer guaranteed --> worsen the CAD/induce economic crisis' (1997 Asian crisis, 2002 Argentina)
○ Higher CAD means the adoption of contractionary macroeconomic policies --> deter consumer spending and confidence --> low economic growth
in the short run○ More volatile exchange rates - high CAD can reduce investor confidence --> reducing the demand for the AUD --> resulting in a depreciation (a depreciation can also mean the value of foreign debt can increase)
○ The balance of payments constraint - a bit like a speed limit; the extent which the economy's ability to grow is constrained by the need to keep the CAD sustainable (as higher eco growth means more imports, bigger outflows, which worsens the CAD)
overall, Australia's persistently high CAD isn't a problem, as Australia invests in income returning assets, and the generated income does not facilitate the debt trap
They are a bit brief but I hope they make sense with all the arrow --> nonsense