The dummy variable is 0 or 1, but obviously the years of education cannot be simply expressed in two states. Cannot be used as a dummy variable.

Virtual variables, also known as dummy variables, nominal variables or dummy variables, are artificial variables used to reflect the quality properties, and are quantitative independent variables, usually with the value of 0 or 1. The introduction of dummy variables can make the linear regression model more complicated, but the description of the problem is more concise, and one equation can achieve the effect of two equations, which is closer to reality.