Cast your eye over a list of the mintage figures for Australian sovereigns throughout the 1920's, and you'll see that this period is one of extreme volatility – it includes the rarest coin in the entire Australian sovereign series (the 1920 Sydney), as well as what is arguably the most common coin in the entire sovereign series – the 1925 Sydney.
This volatility in production was not caused by any one single factor – changes in Australia's national economic output; declining gold production; significant changes to exchange rates and the repatriation of Australia's national debt following the end of World War I all played a role in pushing the quantity of Australian sovereigns struck (and more importantly, the quantity of Australian sovereigns released) to previously unforeseen highs and lows.
The Australian Economy Rebuilds After WWI
The declaration of armistice in 1919 was seen by many as the dawn of a new age for Australia. The ANZAC forces returned from the front with every intention of returning to work and daily life at home as soon as the celebrations and reunions were out of the way.
With the austerity and price controls of the war a recent memory, Australians the nation over set about re-building their lives. This increased spending, coupled with the repatriation of 250,000 servicemen and women (a number equal to 5% of Australia's wartime populationi) saw inflation rise and remain in or close to double digit figures throughout much of the 1920's.
Australia's Gold Production Declines Throughout the 1920's
The highest grade ores of West Australia's “Golden Mile” were eventually exhausted throughout the 1920's, the logical consequence of which was that the quantity of gold ore received by Australia's mints declined also.
Although the gold boom of the 1980's showed that the Golden Mile still had many millions of ounces of wealth contained in it, the limits of the best available mining and refining technology of the day meant that by the early 1930's, as much gold as could be economically mined in Australia was already out of the ground.
The costs associated with additional mining were prohibitive, and no new easily accessed fields had been found for some time. Industrial disputes further exacerbated the difficulties associated with gold mining in Australia in the 1920's, and the mintages of Australia's sovereigns spiralled downwards as a result.
Repatriation of Australia's Wartime Debt
The annual reports of the Australian branches of the Royal Mint of the 1920's make liberal references to “specie” (coinage) being forwarded to the Commonwealth Treasury (via the Commonwealth Bank) as soon as it was struck. All of the sovereigns struck from gold ore supplied by members of the Australian Gold Producer’s Association was sold overseas, ensuring that the number of sovereigns introduced to circulation was minimal at best.
The war had been ruinously expensive for the British Commonwealth. After expending £377m, the Australian Government ended the war with loans of £262.5m, including a debt to the United Kingdom of £43.4m, or 68% of GDP.