Table 2 Descriptive statistics of the main variables
| Â | Definition | N | Mean | Std. Dev | Min | Max |
|---|---|---|---|---|---|---|
Panel A: Outcome variables | ||||||
 WISC-IV scores | WISC-IV test scores | 472 | 88.258 | 10.948 | 59 | 124 |
 Fluid Intelligence | The average of working memory, perceptual reasoning, and processing speed scores | 472 | 8.472 | 1.684 | 3.667 | 13.333 |
 Crystal intelligence | The verbal comprehension score | 472 | 7.928 | 2.577 | 2 | 16 |
 Similarities | Scores of scale | 472 | 7.928 | 2.577 | 2 | 16 |
 Digit span | Scores of scale | 472 | 8.117 | 2.507 | 2 | 17 |
 Coding | Scores of scale | 472 | 9.71 | 2.481 | 2 | 19 |
 Matrix Reasoning | Scores of scale | 472 | 7.591 | 2.238 | 1 | 17 |
 Raven's IQ | Raven's test scores | 2503 | 93.641 | 17.511 | 5.35 | 133.3 |
 Math scores of 2016 | Standardized math scores | 5188 | .02 | 0.996 | -2.071 | 2.517 |
 Extraversion | Scores of scale | 5166 | 3.349 | 0.562 | 1.125 | 5 |
 Agreeableness | Scores of scale | 5166 | 3.739 | 0.536 | 1.444 | 5 |
 Conscientiousness | Scores of scale | 5166 | 3.279 | 0.570 | 1.111 | 5 |
 Neuroticism | Scores of scale | 5166 | 2.913 | 0.625 | 1 | 5 |
 Openness | Scores of scale | 5166 | 3.411 | 0.569 | 1.3 | 4.9 |
Panel B: Student Characteristics | ||||||
 Boarding | 1 = Student is boarding at school | 5660 | 0.460 | 0.498 | 0 | 1 |
 Student age | A student’s age in years | 5660 | 12.917 | 0.964 | 10 | 17 |
 Student gender | 1 = Male; 0 = Female | 5660 | 0.499 | 0.500 | 0 | 1 |
 Left-behind child status | 1 = Father or mother migrated to a city for work for more than six months in the past year | 5660 | 0.525 | 0.499 | 0 | 1 |
 Father's education level | 1 = Junior high school and above 0 = Junior high school below | 5660 | 0.359 | 0.480 | 0 | 1 |
 Mather's education level | 1 = Junior high school and above 0 = Junior high school below | 5660 | 0.213 | 0.410 | 0 | 1 |
 Family asset value | Indicators of wealth in the family | 5660 | -0.001 | 1.074 | -1.496 | 3.019 |
 Math scores of 2015 | Standardized math scores | 5660 | -0.112 | 0.974 | -3.167 | 2.551 |
Panel C:School Characteristics | ||||||
 School size | Number of students | 5660 | 217.91 | 96.641 | 46 | 447 |
 Teacher-student ratio | Number of teachers per student | 5660 | 0.137 | 0.065 | 0.039 | .474 |
 Time required for the school to be the furthest administrative village | hours | 5660 | 1.22 | 0.777 | 0.05 | 4 |
 The rate of school boarders | The number of boarders divided by the total number of students in the school | 5660 | 0.469 | 0.409 | 0 | 1 |
Panel D:Teacher Characteristics | ||||||
 Teaching years | years | 5660 | 9.072 | 6.954 | 0 | 38 |
 Teacher’s gender | 1 = Male; 0 = Female | 5660 | 0.636 | 0.481 | 0 | 1 |
 Teacher's education level | 1 = junior college above 0 = junior college and below | 5660 | 0.517 | 0.500 | 0 | 1 |
 Teacher’s age | A teacher’s age in years | 5660 | 32.499 | 5.869 | 22.332 | 56 |
 Teacher’s title | 0 = have no title;1 = third-grade title;2 = second-grade title;3 = first-grade tltle;4 = Senior professional title | 5660 | 1.093 | 1.005 | 0 | 4 |