Adam Przeworski and Fernando Limongi published a study in 1997 in the World Politics Journal. It was entitled "Modernization: Theories and Facts." In the study, they looked at every country between 1950 and 1990 to correlate economic development and democracy building. They found that in a democratic country that has a per capita income of under $1,500 (adjusted for inflation here), the regime on average lasted about eight years. Between $1,500 and $3,000, it survived for about eighteen years. Any per capita above $6,000, democracy usually worked (the chances of it dying were 1 in 500). Every country that started their democracy when per capita was $9,000 have all lasted. None of the 32 countries in that category have died.
If you read the new 2004 Human Development Report on the United Nations site, you'll find that China's per capita GDP is at $4,580. Growth of per capita income is a mixed bag. Rural residents are seeing a decline in their speed of growth, which is now somewhere around 2 percent. Urban residents, however, are seeing slight increases in growth, which is currently growing at a pace of 7 percent.
Iraq's per capita income is obviously distorted with the previous ten years of sanctions. Nonetheless, whatever the cause may be, there is some concern that Iraqi per capita income is $480. And it's declining.