What is the reason for the negative population growth in Shanghai for 16 years?

1. Policy control: The China government has adopted a series of population control policies, such as the household registration system and the population control plan, aiming at controlling the population size and growth rate of big cities to meet the challenges and pressures brought by urban development. These policies may have a certain impact on Shanghai's population growth.

2. Economic development: As the economic center of China, Shanghai attracts a large number of people, especially those from other regions, to seek employment and development opportunities. However, changes in the level of economic development and opportunities may affect the scale of population inflow.

3. Cost of living and competitive pressure: As a developed city, Shanghai has a relatively high cost of living and is also facing fierce competitive pressure. This may make some people choose to look for more suitable development opportunities elsewhere instead of staying in Shanghai.

It should be pointed out that population growth is a complex problem, which is influenced by many factors. Therefore, regarding the specific situation of Shanghai's population growth, it is suggested to refer to relevant official data and research reports to obtain accurate and detailed information.