In recent months, some people in the world have made predictions about China's economy. In an interview last August, former US Treasury Secretary Thomas Summers compared China today to Japan in 1990. A recent study by the Japan Economic Research Center expressed a similar view. Paul Krugman, a columnist of the New York Times, believes that China is facing a serious aging problem, and the economy's dependence on real estate investment is unsustainable. Summers made a simple mistake. The population of China is more than four times that of the United States, while the population of Japan is only one third of that of the United States. It is really unreasonable to think that Japan will surpass the United States in terms of total income, because it means that Japan's per capita income will be three times that of the United States. However, as long as China's per capita income is close to 1/4 of that of the United States, it is not difficult to achieve the goal of exceeding the total amount of the United States. Most other expectations that look down on China's growth prospects are based on the low forecast of China's future potential growth rate. For example, the Japanese Economic Research Center simply assumes that China's potential growth rate will continue to decline in the next few years, and will converge to the level of the United States by 2035, that is, 2.2%. Based on this assumption, they concluded that China will never catch up with the United States. China's real potential growth rate forecasting a country's potential growth rate is very important for judging its economic trend, but it is not easy. According to Robert Solo's neoclassical growth model, the growth rate of total factor productivity and the growth rate of population are two effective indicators for predicting the potential growth rate of mature economies. The former can measure the improvement of the overall efficiency of an economy, which is mainly reflected in technological progress and institutional improvement. It is widely believed that the potential growth rate of the US economy is about 2.2% annually. The potential growth rate of catch-up economies depends on the capital accumulation rate and total factor productivity growth rate. With this in mind, one can generally estimate China's current and future potential growth rates. China's household savings account for 45% of GDP, while the productive capital stock is 3.6 times of GDP. Assuming that all savings are converted into capital, China's capital stock will grow by 12.5% annually. Most of China's infrastructure is relatively new, with a reasonable annual depreciation rate of 5%. Thus, the annual net growth rate of China's productive capital is 7.5%. Since the contribution of capital to production is 50%, it can be calculated that the contribution of capital accumulation to potential growth is 3.75%. We need to realize that the vast majority of TFP measurement indicators are derived from the so-called "Solo residual", so they are pro cyclical to a large extent. China's economic growth has slowed down in the past decade, and some researchers have concluded that China's total factor productivity growth rate is extremely low or even negative. However, even so, the lower limit of total factor productivity growth in China's potential growth rate is 20%, and the upper limit can reach 40%. Based on 3.75%, China's potential growth rate will be between 4.7% and 6.3%, averaging 5.5%. In the next few years, China's household savings rate will decline. In fact, the household savings rate has declined since 2010