For example, air pollution in China is a public resource, and many unscrupulous enterprises discharge a lot of waste gas into the air. Enterprises don't have to bear enough pollution discharge costs, causing damage to others' health and paying extra health costs, such as medical expenses. China's mobile, telecommunications and other monopoly industries are not in a competitive state. Controlling prices is the performance of the invisible hand in the free market, which leads to the ineffectiveness of the invisible hand and people pay high communication fees.