Independent variable

Assignment

Social status

Occupational risk

Title

Age

Gender

School performance

Class cadre experience

Glorious = 1, superior to other professional = 2, not respected = 3;

Very large = 1, relatively large = 2, general = 3, very small = 4;

Have title = 1, no title = 2;

<25 = 1, ≥25 = 2;

Male = 1, female = 2;

Outstanding = 1, good = 2, general = 3, poor = 4;

Have =1, no = 2.