What is the ideal population of China?

In terms of China's grain and land resources, the ideal population base of China should be between 7-1billion, and10.5 billion is the limit. From the perspective of resource allocation, the ideal population base of China should be around 700 million. China's current population has exceeded the limit that the land can bear ... The reason for calling for a second child is that family planning has expired for nearly ten years, which will lead to a sharp decline in China's population and a shortage of labor in the coming decades. In fact, according to the original family planning policy, family planning seems to last for about ten years, and then it was delayed for more than ten years because of the interest disputes of the members of the relevant departments, resulting in a shortage of labor in the next few decades. Therefore, it is a pity that not many people respond to the call for a second child. Well, I am also a determined not to have a second child: D.