Interpretation of Regression Coefficients

Consider a multiple regression analysis conducted to determine the impact of education level (measured in years of schooling), experience (measured in years), and age (measured in years) on the annual income of individuals. The regression equation estimated is as follows:

$$ ext{Income} = eta_0 + eta_1 ext{Education} + eta_2 ext{Experience} + eta_3 ext{Age} + ext{error} $$

Where:

• $$ eta_1 $$ represents the increase in income for each additional year of schooling, holding experience and age constant.
• $$ eta_2 $$ denotes the increase in income for each additional year of experience, holding education and age constant.
• $$ eta_3 $$ indicates the impact of each additional year of age on income, controlling for education and experience.

After estimating the model, the following coefficients were derived:

• $$ eta_0 = 20,000 $$
• $$ eta_1 = 3,000 $$
• $$ eta_2 = 1,500 $$
• $$ eta_3 = 200 $$

Given this information, which of the following statements regarding the regression coefficients is correct?