The US has a much higher human development index (HDI), which it ranks 4th compared to China which ranks 101st. However, prevalence of HIV/AIDS and obesity among adults in the US is 6 times and 12 times more than of that in China respectively. The average life expectancy in China stands at 74.8 years, slightly lower than 78.4 years in the US, which can be attributed to higher incomes and better healthcare in the US.
The US is one of the world's most ethnically-diverse and multicultural nations due to large-scale immigration from countries all over the world. Migration rates in the US stand at 3.62/1000 people, in stark contrast to China's which is -0.33/1000 people. And even though China has a lower urbanization percentage at 51.3% as compared to 82.0% in the US, it has a higher urbanization rate of 2.3% to 1.2% of the US'.
China's literacy rate of 95.9% is also sightly lower than the US' 99.0%. In the 2009 international PISA test taken by 15-years-old students, Chinese students have shocked the world by topping the scores in all reading, math and science subjects, while the Americans ranked in the middle range, a position they have held for a long time. This can be attributed to the hardworking attitudes of the Chinese.
Due to the one-child policy that has been implemented in China since 1970 to prevent its population from exerting huge strains on the country's limited resources, the population growth rate in China is at a shockingly low figure of 0.481% as compared to 0.899% in the US. A social mindset which favours males over females has also resulted in an imbalanced sex ratio of 1.17 males for every female under the age of 15 in China as compared to 1.05 males per female in the US. Forced abortions of female foetuses occur comparatively frequently, especially in rural areas of China where people still hold on to outdated thinkings like favouritism for males.
Even though China's main political party is called 'The Communist Party of China (CPC)', China's model is one of socialism with Chinese characteristics, and has embraced capitalism fervently. This has no doubt caused much misconceptions about the Chinese social and political model, with many retaining the thinking that China is communist or even a dictatorship.
The CPC is the world's largest political party comprising of approximately 80 million members nationwide. Leaders are replaced and the cabinet is reshuffled once in a decade, with the President and Premier and other members of the Politburo Standing Committee being elected internally by top party members instead of the citizens.
China has vowed to bring about political reforms, but stated that its priority is currently economic reforms. Small democratic experiments have been made at the local level, with elections for the village committee members being held. One notable example would be the southern Chinese fishing village of Wukan in Guangdong Province. The CPC has also dedicated Shenzhen, a miracle of economic reform, as the first mainland city to hold democratic elections in a bid for political reform.
On the other hand, the US is one of the world's most democratic nations, with the two main political parties being the Republican and the Democratic Parties. The President of the United States is being elected by the people every term, which lasts four years. This model of governance is being exported and encouraged in other developing nations, especially in the wake of the Arab Spring. This sometimes-intrusive replication of the democratic model without regard for local historical and cultural contexts results in many conflicts between locals and Americans, which partly explains the hostile sentiments of muslims in the Middle Eastern states towards Americans.
The United States is far more superior when concerning nuclear weapons and has a much higher budget for military. China is raising its military expenditure year-on-year in a bid to catch up with the US' superiority in military technology.
The result of war pitched between these two superpowers remains inconclusive, though many agree that both could completely wipe out every other country on Earth with a snap of their fingers due to their huge nuclear arsenal. In this, they are usually considered to be equal.
From the fall of the Qing Dynasty to the Mao era, China underwent a series of industrial revolutions in an attempt to catch up with western powers. However, there were many obstacles and failed policies that did not result in the emergence of a strong economy during that time, for example, the Japanese invasion during World War II and Mao Zedong's 'Great Leap Forward'.
After the Mao era, Deng Xiaoping, Mao's successor, initiated a series of economic reforms in the 1980s, introducing a free market system and abolishing government control on the matter. This vastly improved the standards of living in China.
In the US, economic freedom had always been in place, allowing it to prosper and advance dramatically. In comparison to China, the United States only had one industrial revolution. However, it was enough to push it to a superpower level next to Great Britain in the 1800s.
The gross domestic product (GDP) of the United States, both total and per capita, remains substantially higher than China's. However, the labor force, growth rate, and rate of unemployment in China is significantly better than in the United States.
The United States also has a substantially higher national debt than China. Its federal reserves of gold are also lower than China and it tends to import more than it exports, resulting in an unfavorable trade balance. In contrast, China exports more than it imports, has little national debt, and has lower government expenditures. However, the United States outranks China in all energy resource productions.
China also holds the world's largest foreign-exchange reserves, standing at US$3.24 trillion as of Jun 2012. This is in stark contrast to the US' US$150 billion.
On the individual level, the US far outstrips China in terms of the number of High Net Worth Individuals (HWNIs). The US has 412 billionaires and 3,068,000 millionaires while China has only 95 billionaires and 562,000 millionaires in 2011. However, due to macroeconomic effects of both countries, the growth rate of number of HWNIs in China races ahead, with a 5.0% growth from 2010 to 2011, while the US suffered a decline in number of HWNIs during the same period.
The United States has a much higher GDP per capita as compared to China. Due to the fact that the US has less than 25% of China's population and a little less than 3 times of China's GDP, the US has a GDP per capita of more than 10 times that of China. As such, for China to overtake the US in terms of GDP per capita, it would have to raise its GDP to more than 4 times that of the US. As a result, it would most likely experience an unusual phenomenon: It will exist as both a developed and developing country at the same time, based on total GDP and GDP per capita respectively.
There are various discussions on the environmental impacts due to industrialization. In 2007, China overtook the US to become the world's largest emitter of all greenhouse gases, also in top place for emissions of sulfur dioxide, carbon dioxide, CFCs and other ozone depleting substances. China has also overtaken the US to become the world's largest oil consumer in 2010. According to the World Bank, China is home to 20 of the 30 most polluted cities in the world, due to unhealthily large amounts of emissions by factories, motor vehicles and coal mining, with the most polluted city, Linfen, located in China. Loose environmental laws and regulations are also to blame.
However, China has been investing heavily in green technology. In 2010, China overtook the US in terms of green investment. Its green investment expands in all fields. It currently has the Three Gorges Dam, the world's largest dam in terms of energy production, and Dabancheng Wind Farm, the largest wind farm in Asia. It is planning the world's largest solar farm in Qinghai, made significant improvements in green vehicles and came up with tight transport regulations such as the one on car usage in Beijing.
It must also be noted that China has a population of more than 4 times that of the US, so in terms of emissions per capita, such as carbon dioxide, the US, although not top in the world, is about 4 times that of China's. Moreover, China, dubbed the factory of the world, houses factories from all around the world. This means that emissions are exported to China from developed countries in the form of factories, and it is reported to make up about 40% of all emissions.