School construction started in 1973 and was complete by 1978. We will assume, for simplicity, that the treated children are 2-6 years old in 1974 and control children are 12-16 years old in 1974.

• The average years of schooling for 2-6 years (treated children) old children in high intensity county is 6 years and in low intensity county is 9 years.
• Similarly, the average years of schooling for control children (12-16 years old) in high program county is 5 years and in low program county is 11 years.
• Using this information, estimate the impact of this program on years of schooling and answer the following questions:
  1. What is the intervention? (0.5 point)
  2. What is the outcome researcher are primarily interested in? 
     1. c. Which method does the author use to estimate the program’s impact?