The People's Republic of China is the world's largest country by population, the second largest by land area, and continues to emerge as a major economic and military power. Modern China has evolved from one of the oldest civilizations known to man. For thousands of years, China was rule by hereditary dynasties. Modern China is centrally governed by the Communist Party. The Yangtze and Yellow Rivers are two of the largest river systems in the world. China implemented economic reforms in 1978 and has since become one of the fastest growing economic powers in the world. The country is known as an Asian regional power that is sometimes described as a potential super power by political analysts around the world. Beijing is the capital city. When it was formed in 1949, The People's Republic of China mandated a planned economy that was based on state controlled collective farms and industry. This caused the economy to lag behind those in the developed world that were more market oriented and based on capitalism. In 1978, the government implemented economic reforms that allowed for more private enterprise with less government intervention. This state-capitalism has enabled China to grow its economy at a very fast rate. China is now home to the second largest concentration of the world's billionaires, but there is a very large discrepancy in per capita wealth. The fast rate of economic expansion has also met with some problems like rapid inflation and some downturns in the overall economy. Even though it has implemented economic reforms, China is still a socialist state that endorses communism. The upper echelons of the ruling party elects their single party members from within. Lower level provincial leaders do have a relatively high level of autonomy. The President of China is a ceremonial figurehead and head of state for the National People's Congress. At the town and village levels, there is a level of political liberalization, but the Party still has control over most political positions. Chinese society has changed dramatically since the late ownership over the recent decades. More and coal powered industries have made parts of China some of the most polluted in the world. The youth of China seem to be more embracing of the western lifestyle but the ruling Party keeps tight control on Internet communications as well as individual expression.