I quite like the topvoted answer in this thread. Perhaps another user will have more to contribute, or you can use the /u/ function to ping the person who answered this question if you have follow-ups.

Local political movements which would have been considered radical in England and Europe were important: Free-Selection (similar to US Homesteading) created, if only for a generation, a numerous class of small landowners in rural areas who produced a local market for goods and voters who encouraged a more egalitarian distribution of wealth. This also lead to the extinction of large landowners as a political class. De-militarisation. As the redcoats left each colony there was no serious attempt to replace them and thus no professional military class. An ambitious young man would never consider military life, instead taking his talents to business or government. There was also no big expenditure on the military. Government spending on infrastructure - roads, railways, ports. This helped internal trade and the free movement of labour. Centralised government growing out of the convict administration. "Australia had a government before it was a nation." A strong central colonial government created uniformity of laws, policing and administration and diluted the power of local oligarchies. The rise of popular democratic institutions - trades union, farmers' co-operatives, building societies (like US Savings & Loans), progress associations, Mechanics' Institutes all helped with the redistribution of wealth downwards. A prosperous working class/lower middle class spends their money locally on food, housing, clothes and household items. By contrast the wealthy tend to favour high-return investments, which might not be best for he national economy, leading to economic stagnation. With a prosperous working class and middle class and a comparatively small upper class political parties tended to favour the social-democratic centre. See Roberts, Stephen H., History of Australian Land Settlement, 1788-1920, Macmillan / Melbourne University Press, Melbourne, 1924. Holthouse, Hector, Up Rode the Squatter, Rigby, Sydney 1970.