伴随着人均预期寿命的延长和生育率的下降，我国人口老龄化日益加剧。为了应对人口老龄化带来的挑战，“十四五”规划提出，“实施积极应对人口老龄化国家战略”，“逐步延迟法定退休年龄，促进人力资源充分利用”。目前我国法定退休年龄相对较早，随着居民生活水平的提高、医疗卫生条件的改善以及数字化技术的发展，实际劳动年龄也在不断上升，这也为积极开发老龄人力资源提供了有利条件。促进老年人力资源的开发利用，对激发低龄老年人的社会参与积极性，缓解劳动力市场供需矛盾，减轻社会养老负担和促进社会经济发展等方面均具有重要作用。探究我国城镇低龄老年劳动供给问题具有重要学术意义和现实意义。

本文主要基于城镇住户调查数据（UHS）、中国居民收入调查数据（CHIP）、中国健康与养老追踪调查数据（CHARLS）等微观数据库，首先分析了城镇低龄老年人口的劳动供给基本特征事实；其次，关注影响老年人劳动供给的内在因素，从自身健康角度探究老年劳动供给问题；再次，关注社会经济政策外部因素，从最低工资政策视角探究老年劳动供给问题；最后，关注老年人劳动供给的社会经济效应，探究老年人与中青年群体劳动供给之间是否存在替代的关系。本文的主要研究结论如下：

（1）与OECD主要国家相比，我国城镇低龄老年人的就业比重明显更低。相比于中青年群体，城镇低龄老年人更加倾向于以非正规就业方式参与劳动力市场。Age-Period-Cohort模型的估计结果显示，随着年龄增长，个体的就业意愿、工作时间和劳动收入生命周期形式均呈现“驼峰状”，在老年期的就业概率、工作时间和劳动收入水平明显更低。

（2）城镇低龄老年人自评健康随年龄增长无明显变化趋势，慢性病数量随着年龄增长则呈现较快上升趋势，其中患病率相对较高的是高血压、血脂异常、糖尿病、慢性肺部疾患、心脏病、胃部疾病和关节炎七种慢性疾病；老年人的心理健康随着年龄增长呈现缓慢上升趋势。区分不同群体异质性来看，男性和高教育群体的自评健康整体上好于女性和低教育群体；女性群体所患慢性病数量相对更高，不同教育群体差异并不明显；女性和低教育群体心理健康状况相对更差。

（3）在估计健康状况对城镇低龄老年劳动供给行为影响方面，结果表明主观身体健康、客观身体健康和心理健康均对老年就业存在显著影响；采用横截面数据分析将会带来估计偏误，有必要控制个体初始健康、就业、财产等状况。采用主观身体健康指标时，结果表明主观身体健康存在测量误差问题，辩解偏误（justification bias）问题可能相对较小；采用客观身体健康指标时，若只采用少数几种慢性疾病，将会低估真实健康状况对就业的影响程度，在充分考虑多种客观身体健康指标时，能得到与主观身体健康指标相似的估计结果；采用心理健康指标时，若忽略身体健康状况，将明显高估心理健康对老年就业的影响。从理论模型机制分析来看，健康主要通过影响城镇低龄老年人的闲暇偏好、生产率、疾病补助、对健康和工作的预期、寿命预期等五个渠道影响其劳动供给行为。在健康状况对城镇低龄老年人就业下降的解释力度方面，结果表明身体健康解释了55至70岁之间城镇低龄老年人就业比重下降的25.8%；心理健康对就业下降的解释力度只有1.1%。在工作时间和工资方面，健康状况的改善对城镇低龄老年群体的工作时间和工资水平均有显著正向影响。此外，本文也发现健康状况的改善将显著提高城镇中老年群体的预期退休年龄。

（4）最低工资标准上涨显著提升了城镇低龄老年群体的劳动参与概率和就业概率。从不同群体异质性来看，最低工资标准上涨主要影响男性、教育水平较低、低财产性收入、低养老金收入和来自东中部地区的城镇低龄老年群体。从不同就业类型来看，最低工资政策显著提高了城镇低龄老年群体进入正规部门就业和离退休再就业的概率，降低了离退休的概率。最低工资标准上涨也显著提升了城镇低龄老年群体的工资水平。

（5）城镇低龄老年人就业并不会挤出中青年群体的就业，而是对中青年就业有显著正向影响，且主要显著提升了25至49岁中青年群体的就业，对20至24岁青年群体的就业没有显著影响。区分不同群体异质性来看，城镇低龄老年人就业对女性和低技能水平的中青年群体的就业正向影响更大。机制分析表明，城镇低龄老年就业比重的提高显著促进了老年群体消费水平的增加，也提升了社会总需求，一定程度上带动了中青年群体的就业。此外，在短期内，城镇低龄老年人劳动供给的增加对中青年群体的工资水平无显著影响，而中青年群体劳动供给的增加会降低其自身的工资水平。

基于上述的研究，本文认为需要通过加强对老年人的健康教育，完善基本卫生公共服务和医疗救助制度等方面建立健全“健康老龄化”相关政策；通过渐进式延迟退休政策和弹性退休制度使得部分有就业意愿的低龄老年人继续留在劳动力市场，一方面能提升该部分低龄老年群体的收入水平，并促进社会经济的发展，另一方面也能够减轻公共养老财政负担；通过优化老年劳动力市场就业政策，合理提高最低工资标准水平，完善老年就业公共服务平台，搭建老年人力资源服务体系，为老年人提供相关就业服务，为有就业意愿老年人提供工作信息、工作指导和相关技能培训。从而有助于积极应对人口老龄化问题。

With the prolongation of life expectancy and the decline of fertility rate, the aging population in China is becoming increasingly severe. In order to cope with the challenges brought by population aging, the “14th Five-Year Plan” proposed to “A national strategy in response to population aging” and “the statutory retirement age will be raised in a phased manner to give full play to the potential of human resources”. At present, the statutory retirement age in China is relatively early. However, with the improvement of residents' living standards, the improvement of medical and health conditions, and the development of digital technology, the actual working age is also rising. This also provides favorable conditions for the active development of elderly human resources. Promoting the development and utilization of elderly human resources is important for stimulating the enthusiasm of the low-age elderly to participate in society, alleviating the supply-demand contradiction in the labor market, reducing the social pension burden and promoting social and economic development. Exploring the issue of low-age elderly labor supply in urban areas of China has significant academic and practical implications.

This article is mainly based on micro-databases such as Urban Household Survey (UHS), China Household Income Project (CHIP), and China Health and Retirement Longitudinal Study (CHARLS), etc. Firstly, this paper analyzes the basic characteristics of labor supply of low-age elderly population in urban areas; Secondly, this paper focuses on the intrinsic factors affecting elderly labor supply, and explores the issue from the perspective of their own health; Once again, this paper examines the issue of elderly labor supply from the perspective of minimum wage policy as an external socio-economic policy factor; Finally, the research explores the socio-economic effects of elderly labor supply for the elderly and investigates whether there is a substitute relationship between elderly and middle-aged labor supply. The main research conclusions of this paper are as follows:

 (1) The employment rate of the low-age elderly in urban areas of China is significantly lower compared with major OECD countries. Low-age elderly in urban areas are more inclined to participate in the labor market through informal employment than middle-aged groups. The estimation results of the Age-Period-Cohort model show that as individuas age, their willingness to work, working hours and labor income all exhibit a “hump-shaped” lifecycle pattern, with significantly lower employment probabilities, working hours, and labor income levels during the elderly period.

 (2) The self-assessed health low-age elderly people in urban areas shows no significant trend as they age, while the number of chronic diseases increases rapidly with age. The most prevalent chronic diseases are hypertension, dyslipidemia, diabetes, chronic lung disease, heart disease, stomach disease and arthritis. The mental health of the elderly shows a slow upward trend as they age. When considering the heterogeneity of different groups, men and those with higher education generally have better self-rated health than women and those with lower education. Women have a higher number of chronic diseases, and the difference among education levels is not significant. Women and those with lower education have relatively poorer mental health.

(3) In terms of estimating the impact of health status on the labor supply behavior of the urban low-age elderly, the results show that subjective physical health, objective physical health and mental health all have significant effects on elderly employment. Given that cross-sectional data analysis is prone to estimation bias, so it is necessary to control for individual initial health, employment, property, and other conditions. When using subjective physical health indicators, the results show that there is a measurement error issue with subjective physical health, and the problem of justification bias may be relatively small. When using objective health indicators, if only a few chronic diseases are used, the degree of impact of real health status on employment will be underestimated. However, with full consideration of multiple objective physical health indicators, similar estimation results to subjective physical health indicators can be obtained.  when using mental health indicators, if the physical health status is ignored, the impact of mental health on elderly employment will be significantly overestimated. From the perspective of theoretical model mechanism analysis, health mainly affects the labor supply behavior of the urban low-age elderly through five channels: leisure preference, productivity, disease subsidies, health and job expectations, and life expectancy. In terms of the role of health status playing in the employment change of urban low-age elderly, the results show that physical health account for 25.8% of the employment decline of urban low-age elderly between the ages of 55 and 70; mental health explained only 1.1% of the employment decline. In terms of working hours and wages, the improvement of health status has a significant positive impact on the working hours and wage levels of the urban low-age elderly group. In addition, this article also found that the improvement of health status significantly increases the expected retirement age of urban middle-aged and elderly groups.

(4) The increase in the minimum wage has significantly improved the labor participation probability and employment probability of the urban low-age elderly groups. From the perspective of heterogeneity among different groups, the increase in the minimum wage mainly affects male, low-skilled, low-property income, pension-income and elderly groups in the eastern and central regions. Regarding different types of employment, the minimum wage policy significantly increases the probability of the urban low-age elderly people entering formal employment and re-employment after retirement, while reducing the probability of retirement. The rise in the minimum wage has also significantly increased the wage level of the urban low-age elderly.

(5) The employment of young and middle-aged people in urban areas does not lead to the displacement of young and middle-aged workers. Instead, it has a significant positive impact on the employment of young and middle-aged workers, particularly those aged 25 to 49, with no significant effect on the employment of young people aged 20 to 24. When different population heterogeneities are distinguished, the employment of elderly people in urban areas has a greater positive impact on female and low-skilled young and middle-aged workers. Mechanism analysis shows that the increase in the proportion of elderly people’s employment in urban areas significantly promotes the increase in their consumption level and the overall social demand, which to some extent drives the employment of young and middle-aged groups. In addition, in the short term, the increase in the labor supply of the urban low-age elderly has no impact on the wage level of the young and middle-aged groups, while the increase in the labor supply of the young and middle-aged groups will lovwer their own wage level.

Based on the above research, this paper believes that it is necessary to establish sound policies related to “healthy aging” by strengthening health education for the elderly, improving basic public health services and medical assistance systems, and so on. Through implementing a progressive delay in retirement policies and flexible retirement systems, some low-age elderly people with employment intentions can continue to stay in the labor market. This can not only improve the income level of this group of low-age elderly people and promote the development of the society and economy, but also relieve the financial burden on the public pension. By optimizing employment policies in the elderly labor market, reasonably increasing the minimum wage standard, improving the elderly employment public service platform, and building a senior human resources service system, relevant employment services can be provided to the elderly. Work information, job guidance, and relevant skills training should be provided for the elderly with employment intentions. This will help to actively address the issue of population aging.