It has been 30 years since China embarked on the greatest economic experiment in human history. In that time, the country has emerged from poverty and chaos to become one of the leading economic powers. It is tempting to call China's astounding growth an economic miracle, but the trajectory of the last three decades has been the product of planning, innovation and carefully tended capitalism. Today, China confronts many of the old challenges — growth has been uneven, leaving many Chinese untouched by the fruits of success — and new ones too. The current economic crisis and new constraints imposed by energy shortages and climate change demand new thinking every bit as bold as that embraced in 1978.

Three decades ago, China's future was uncertain. The Cultural Revolution was a blight on the nation's soul and left and right battled for supremacy in the post-Mao world. On Dec. 8, 1978, the wily survivor Deng Xiaoping was named head of the Communist Party, and he told the Third Plenum that the country should embrace reform and opening. At that time, the first cautious steps included small-scale private farming, a reversal of Mao's communal agriculture and industry. Farmers' energies — and earnings — were cut loose, left for themselves to enjoy. Two years later, Deng picked Shenzhen, a then quiet fishing village in the Pearl River Delta in southern China, as the site of the first Special Economic Zone to allow foreign investment and export manufacturing. With that, the boom began.

The results have been striking. The economy has grown at an average rate of 9.8 percent since 1978; for more than half that time, growth has been in double digits. Today, China is either the third- or fourth-largest economy in the world. Annual per capita income has gone from 380 yuan in 1978 to about 19,000 yuan ($2,760) in 2007. The number of Chinese living in absolute poverty — less than $1 a day — has dropped from 800 million to more than 10 million. (Millions more live on $1 to $2 a day.) In 1978, the much-sought "four big things" consisted of a bicycle, a radio, a sewing machine and a watch. Today, almost every Chinese home has one television and 15 million families have private cars. Home ownership is on the rise and the country is filled with market watchers who match the enthusiasm (and nervousness) of investors in Tokyo, New York or London.