1. Education popularization demand: With the development of society, people have higher and higher demand for education, hoping to improve their knowledge and skills and enhance their employment competitiveness by receiving higher education. Therefore, in order to meet this demand, the government and schools choose to expand the enrollment scale.

2. The need of economic development: Higher education is an important force to promote economic development, and cultivating high-quality talents is the key to promote scientific and technological progress and industrial upgrading. The expansion of university enrollment can provide more opportunities for higher education and more high-quality talents for the society.

3. Utilize the demographic dividend: Due to the large population base in some countries, a large number of school-age youth need to receive higher education. Through the expansion of university enrollment, we can make full use of this demographic dividend and improve the education level of the people.

4. Policy orientation: In some countries and regions, the government will introduce a series of policies to promote the expansion of university enrollment, so as to realize the modernization of education and improve the quality of the people. For example, the China government implemented the "2 1 1 Project" and "985 Project" in the 1990s, which greatly promoted the expansion of universities.

5. The pressure of international competition: Under the background of globalization, the competition between countries is becoming more and more fierce, and education has become an important part of national competitiveness. In order to improve national competitiveness, some countries will choose to expand the scale of higher education and improve the education level of their citizens.

Generally speaking, the expansion of university enrollment is the comprehensive result of social development, economic development, population policy and international competition.