After the United States withdrew its support for South Vietnam in 1975 and it fell to the North, the victors imposed a traditional "from each, to each" communist economic system.

Richard McGregor is a senior fellow at the Lowy Institute in Sydney and the author of numerous books on East Asia, including, most recently, Xi Jinping: The Backlash.

Their success caused a reaction from inside the Communist Party that saw the rise of these non-state workers as a threat to the system.

Most of the other former communist countries, like Poland and Hungary, rank in the top 50% of economic freedom.

China's Communist Party leaders holds a key meeting on Monday — an opportunity to chart a new economic course — but few observers expect big breakthroughs to boost the economy.