Read the article attached and write a Referee Report： The report should be less than two pages (single space, 12 fonts size, Times New Roman, Normal margin). In the report, you should include the following sections:
• Background and motivation (2 point)
• Research question (2 points)
• Data and study design (2 points)
• Findings and policy implication (2 points)
• Your comments and critiques (2 points)
Use your own understanding to write the report, copy and paste is not allowed.