3.1 Age distribution and regional distribution of health concentration index
Table 2 reports the health concentration index of left-behind children in rural areas, where the positive CI indicates that rural left-behind children from higher income families enjoy better health than those from lower income rural families. The size of the health concentration index represents the degree of inequality in the health of left-behind children in rural areas.
Table 2
Health Concentration Index
Region (number observations) | Age | CI |
Overall(5729) | Under 5 years old | 0.0607 |
| 5-10 | 0.2567 |
| 11-15 | 0.1579 |
East(1934) | Under 5 years old | 0.3683 |
| 5-10 | 0.2835 |
| 11-15 | 0.0817 |
Central(1993) | Under 5 years old | 0.3545 |
| 5-10 | 0.0945 |
| 11-15 | 0.1745 |
West(1802) | Under 5 years old | 0.3760 |
| 5-10 | 0.1553 |
| 11-15 | 0.2790 |
Analyzing the age distribution of left-behind children’s health inequality in Table 2, at the national level the change in the age distribution presents an "inverted U-shape", with the CI the under 5 year olds lowest (0.0607), rising to its maximum value for aged 5 to 10 (0.2567), before falling for children aged 11 to 15 (0.1579). The changes in age distribution of rural left-behind children in the central and western regions show a diverged from the national pattern, with the highest CI in the under 5 age group, next highest in the 11-15 age group and lowest in the 5-10 age group. While the health inequality of left-behind children under the age of 5 in the East, Central and West was the highest, in the East the next highest CI was in the 5-10 age group, diverging from the Central and West regions, where the 11-15 age group had the next highest CI. Across all regions, the under 5 age group, which was the most important period for children's physical development, had the highest health inequality. Disparities in China’s regional development display high to low differences in economic development, health service levels and quality of life (Liao et al., 2020). The regional health inequality was associated with not only the distribution of wealth, but also the distribution of health resources and primary health care services (Fang et al., 2010).
3.2 Analysis of the decomposition results of health inequality
Table 3 presents the results of RIF-I-OLS decomposition. Model 1 is the uncontrolled result for the total sample, and Model 2 is the decomposition result of the health concentration index after adding the control variables for the total sample. Model 3, Model 4, and Model 5 are the results obtained by decomposing samples from the eastern, central, and western regions after adding the control variables. The magnitude and sign of the value directly reflect the magnitude and direction of the impact of the factor on the health inequality of rural left-behind children.
In general, access to medical services, parents migrating, income deprivation, inter-generational care, children’s age, parents’ height and age, children’s and parents’ education levels, family size, and per capita income all played a significant, but different role, in the health inequality of left-behind children. The accessibility of medical services (-0.0548) had a significant negative impact on the health inequality of left-behind children. From the demand-side access, the long travel distance to medical services, inconvenient transport and the lack of financial support to enjoy high-quality medical resources promoted the health inequality of left-behind children. From the perspective of supply accessibility, the quality of medical institutions in rural areas failed to meet the growing medical service needs of rural left-behind children, prolonging the health inequality of left-behind children. As shown from the decomposition results in Models 3-5, the impact of the accessibility of medical services on the health inequality of left-behind children varied by region. The coefficients of the accessibility of medical services show that the impact on the health inequality in West (-0.1211) was significantly greater than in the East (-0.0518) and Central regions (-0.0489). The economic development level and health facilities in the western region was lower than that of the eastern and central regions. Second, the complex and steep terrain and inconvenient transport in the western region greatly affected the distance from, and time to reach, medical treatment, increasing the health inequality of left-behind children.
Table 3
RIF-I-OLS decomposition results
| Total sample | Total sample | East | Central | West |
Model 1 | Model 2 | Model 3 | Model 4 | Model 5 |
Access to medical services | -0.1081*** | -0.0548*** | -0.0518*** | -0.0489** | -0.1211*** |
| (0.0307) | (0.0210) | (0.0079) | (0.0201) | (0.0267) |
Migrant parents | 0.0933** | 0.0327** | 0.0515** | 0.0838*** | 0.0530*** |
| (0.0078 | (0.0136) | (0.0234) | (0.0063) | (0.0171) |
Income deprivation | 0.1003*** | 0.0431*** | 0.0815*** | 0.0416*** | 0.0446*** |
| (0.0249 | (0.0065) | (0.0049) | (0.0072) | (0.0083) |
Intergenerational care | -0.0645** | -0.0498*** | -0.0293*** | -0.0339*** | -0.0904*** |
| (0.0010 | (0.0056) | (0.0060) | (0.0112) | (0.0171) |
Child age | | 0.0006 | 0.0005 | 0.0037 | 0.0101 |
| | (0.0095) | (0.0072) | (0.0121) | (0.0082) |
Child squared age | | 0.0286*** | 0.1015*** | 0.0691** | 0.0230*** |
| | (0.0029) | (0.0115) | (0.0328) | (0.0079) |
Child sex (Boys=0; Girls=1) | | 0.0052 | 0.0332*** | 0.0216*** | 0.0176*** |
| | (0.0375) | (0.0057) | (0.0074) | (0.0045) |
Child education grade | | 0.0205*** | 0.0357*** | 0.0213*** | 0.0368* |
| | (0.0039) | (0.0044) | (0.0079) | (0.0214) |
Parent age | | 0.0798*** | 0.0297*** | 0.0342*** | 0.0507*** |
| | (0.0033) | (0.0057) | (0.0111) | (0.0116) |
Parent weight | | -0.0093 | -0.0118** | -0.0217*** | -0.0515*** |
| | (0.0084) | (0.0058) | (0.0064) | (0.0123) |
Parent height | | 0.0933*** | 0.0183*** | 0.0263* | 0.0299** |
| | (0.0078) | (0.0054) | (0.0141) | (0.0131) |
Parent employment | | 0.0872*** | 0.0172** | 0.0244*** | 0.0233*** |
| | (0.0312) | (0.0079) | (0.0042) | (0.0064) |
Parent education | | 0.0195* | 0.0419*** | 0.0365* | 0.0048*** |
| | (0.0109) | (0.0110) | (0.0211) | (0.0011) |
Family size | | -0.0702*** | -0.0750*** | -0.0308* | -0.1097 |
| | (0.0094) | (0.0148) | (0.0173) | (0.1145) |
Household income per capita | | -0.0274*** | -0.0349** | -0.0123** | -0.0859*** |
| | (0.0096) | (0.0154) | (0.0062) | (0.0140) |
constant | 8.6671*** | 0.5781*** | 0.4422*** | 0.9222*** | 1.3218** |
| (2.8435) | (0.0231) | (0.1143) | (0.2585) | (0.6339) |
Sample size | 5729 | 5729 | 1934 | 1993 | 1802 |
R-squared | 0.1495 | 0.3575 | 0.3339 | 0.3296 | 0.3286 |
Adj R-squared | 0.1341 | 0.3341 | 0.3284 | 0.3116 | 0.3166 |
Notes: Robust standard errors in parentheses, *p<0.05, **p<0.01, ***p<0.001. |
For the full sample in Table 3, migrant parents had a positive impact on the health inequality of left-behind children. Regional patterns in Model 1-3, show that migrant parents in the central (0.0838) and western regions (0.0530) had a significant impact on the health inequality of their left-behind children, usually put down to "lack of care". The impact of migrating parents on health inequality in the eastern region (0.0515) was also significant.
We speculate that distance and travel time by migrating parents impacted the regional health inequality of left-behind children. Migrating rural eastern parents mainly moved to near-by eastern developed cities, remaining relatively close to their home villages, which allowed them to regularly visit their left-behind children. Migrating parents from central and western regions travelled to distant eastern cities, with many western and central migrants not returning home to visit their children for several years.
Income deprivation had a significant positive effect on the health inequality of left-behind children. Overall, the decomposition result of income deprivation on the health inequality of rural left-behind children was 0.0431, but the impact of income deprivation on health inequality had obvious regional differences. Income deprivation in the eastern region was 0.0815, which was much higher than the overall national level and the central (0.0416) and western (0.0446) regions. The economic development level of the eastern region was much higher than that of the central and western regions, so the income gap between different groups in the eastern region was wider than other regions, especially for migrant workers, so there will be a larger gap in the expenditure on child health.
In Table 3, intergenerational care had a significant negative impact on the health inequality of left-behind children. The decomposition results show that the overall influence coefficient of intergenerational tending was -0.0498, where an increase in intergenerational care partially replaces the parent's care function, significantly attenuating the health inequality of left-behind children. From the perspective of regional distribution, the impact of intergenerational care on the health inequality of rural left-behind children in the western region was significantly greater (-0.0904) than that in the eastern (-0.0293) and central (-0.0339) regions. The central and western provinces of China are the main areas of population outflow, while the eastern provinces are important geographical magnets for population inflow. As a result, distance constraints prevent migrating parents from reuniting with their children for long periods of time, and intergenerational childcare in the west and central regions from grandparents took on a large part of childcare, which makes intergenerational care a significant factor in alleviating health inequality.
As shown in Table 3, the age of left-behind children in rural areas had no significant impact on health inequality, but the square term of children’s age had a significant impact on health inequality. The sex decomposition results in the eastern, central and western regions were all positive, indicating that girls were discriminated against. Reflecting traditional values, when a rural family has both girls and boys, the family's health resources were often biased towards male children (Lin and Zhao, 2014). To improve child health, it is necessary to address sex inequality in rural areas. The decomposition results in Table 3 also show that, except for the western region, the education level of left-behind children had a significant impact on health inequality, where the higher the education level, the greater the child’s health knowledge, which was conducive to healthy living habits.
The age of parents (0.0798) also has a significant impact on the health inequality of left-behind children. In Table 3, the older the parents, the lower their working capacity and the less their contribution to family income and childcare, and the wider the health inequality of left-behind children. This impact was most obvious in the western region (0.0507). Generally speaking, parental weight reflects the current nutritional status of the family. For the whole sample, the decomposition results show that parental weight had a negative, but not significant impact, on the health inequality of left-behind children. But, the weight of parents in the central (-0.0217) and western (-0.0515) regions had significant impact on the health inequality of left-behind children, indicating that the nutritional status of parents in the central and western regions was closely related to the health differences of left-behind children. The better the nutritional status of the family, the more conducive to alleviating health inequality. Like weight, height of parents reflects the family’s health endowments, where the height of parents (0.0933) had a significant positive impact on the health inequality of left-behind children. In addition, whether parents work or not had a significant impact on the health inequality of left-behind children. Whether parents work determines the amount of family income and indirectly affects the nutritional environment and the level of medical services available to left-behind children. In Table 3, for the overall sample, the effect of parental education on health inequalities of left-behind children was not significant.
Overall, family size (-0.0702) and family income per capita (-0.0274) had a significant negative effect on the health inequality of left-behind children. The larger the family size, the greater the number of workers to contribute to family income and to family members to care for left-behind children, replacing the care function of absent parents. Family income per capita contributed negatively to the health inequality of left-behind children. Increases in family income per capita, nutritional resources and health services all alleviate health inequality of rural left-behind children.