Foriegn ownership.
Australia has always had a high CAD (apart from 2019-2022) due to the high level of foreign ownership of Australian assets and loose restrictions on foriegn activities here, as well as the savings-investment gap. Many Australian firms cannot find domestic firms to be their investor due to them having insufficient funds for the long term primarily due to Australia’s small population, hence foriegn investment fills the gap (savings-investment gap). Australia also on the other hand has very loose restrictions on foreign investment. For example, Australia is the only major developed country where domestic airlines (excluding QF) can be 100% foreign owned (eg: Virgin) - this is not allowed in the US, UK, Europe (EU) or Canada. This further increases net primary income debits. Australia has relaxed rules on foreign ownership of real estate as well. Australia as a result of these facts and policies, is a net capital importer (more foriegn ownership of Australia than Australian ownership overseas). Australia also does not sufficiently tax multinational mining corporations for taking our resources and extracting it overseas, a big missed opportunity on net primary income. Australia collects more from HECS debt than it does from foreign-owned mining corporations in Australia. So this is all structural/policy factors.
The reason why Australia had a CAS in 2019-2022 was due to record returns on exports offsetting Australia’s payments for imports AND Australia’s debits of interest, repayments, profits and dividends back to foriegn investors and banks. This was temporary and it was always expected to return to deficit.