Comparison of Linear and Non-Linear Regression Models in Analyzing Relationship Between Age and Income

Abstract

Currently, many Chinese people are facing the situation of being laid off during their middle age, and the economic situation was bad and it was becoming increasingly difficult to earn money. This made the author want to figure out what factors exactly could affect a person's salary. In particular, the author wants to explore whether there is a certain relationship between age and salary that can be expressed by a function, and attempts to identify other factors that affect salary. In this article, the author investigated the relationship between age and salary and explored the influence of other variables, such as education level, gender, and the country of residence, on this relationship. Finally, the author conducted hypothesis verification, confirming that this relationship can be expressed by a quadratic function, and then derived a quadratic function formula containing four fixed constants to represent the relationship between age and salary. This study concludes that the relationship between age and salary is best expressed as a quadratic function, influenced by factors such as education, gender, and country of residence.