Table 5. Explained variables and statistical description.
| Variable types | Variable name | Variable definitions | Mean | SD. | Max | Min |
|---|---|---|---|---|---|---|
| basic characteristics of farmers | age | age (years) | 47.83 | 7.23 | 64 | 27 |
| gender | women = 0; men = 1 | 0.67 | 0.47 | 1 | 0 | |
| education level | elementary school level and below = 1; junior high school = 2; high school = 3; university or above = 4 | 2.46 | 0.79 | 4 | 1 | |
| family characteristics | breeding years | cumulative number of years from the beginning of breeding to the present (years) | 12.85 | 3.75 | 24.83 | 2.17 |
| revenue | proportion of pig breeding that accounted for total revenue (%) | 64.23 | 19.83 | 92.16 | 14.54 | |
| welfare variable characteristics of live pigs | farming scale | small = 1; medium-sized = 2; large = 3 | 1.83 | 0.71 | 3 | 1 |
| housed livestock | open = 0; enclosed = 1 | 0.34 | 0.47 | 1 | 0 | |
| waste disposal equipment | do not have = 0; have = 1 | 0.21 | 0.41 | 1 | 0 | |
| science and technology personnel | insufficient = 0; adequate = 1 | 0.43 | 0.5 | 1 | 0 | |
| comprehensive situation of pig welfare | comprehensive pig welfare level | poor = 1; medium = 2; good = 3; optimal = 4 | 1.78 | 0.74 | 4 | 1 |
Note: The scale of farming is based on the "National Compilation of Costs and Profits of Agricultural Products." The number of livestock pigs is 30 to 100 per year for small-scale farmers, 100 to 1,000 for medium-sized farmers, and more than 1,000 for large-scale farmers. The situation regarding local agricultural science and technology personnel is based on their own experience.