| 
 | 模型1 | 模型2 | 模型3 | 
| lninc(2015) | 0.0144** | 0.003 | 
 | 
| 
 | (5.62) | (1.31) | 
 | 
| lninc(2017) | 0.19** | 0.035 | 
 | 
| 
 | (0.073) | (0.087) | 
 | 
| health(2015) | 
 | 
 | 0.05*** | 
| 
 | 
 | 
 | (17.08) | 
| health(2017) | 
 | 
 | 0.34*** | 
| 
 | 
 | 
 | (0.09) |