雙親家庭中母親工作、養育資源以及兒童早期健康與發展

Maternal Employment, Child-Rearing Resources, and Early Childhood Health and Development in Two-Parent Families

施淑芳(Shu-Fang Shih)

指導教授 ： 江東亮

國立臺灣大學/公共衛生學院/健康政策與管理研究所/博士(2011年)

https://doi.org/10.6342/NTU.2011.01381

摘要

研究背景與目的：
近年來，婦女在其生命歷程中的勞動參與率已歷經相當大的改變。其中與該議題相關而受到注目的乃是母親參與勞動市場是否會影響兒童的福祉。直至今日，過去研究對於這個問題以及為何母親參與勞動市場可能會影響兒童早期健康與發展仍未有一致的共識。本研究依據家庭健康生產理論與家庭資源分配理論的協商模型，目的乃是(1)探討母親工作是否可能對早期兒童健康與發展有影響；以及(2)家庭養育資源是否為上述關係可能的中介因子。
方法：
本研究之資料來源為台灣出生世代研究先驅調查。該調查資料收集2003年出生的2,048名兒童之資料，為具全國代表性之樣本。本研究利用該調查之三波資料，分別為兒童六個月、十八個月及三歲之調查資料進行分析。因研究目的所需，本研究限定三波已婚同住之雙親家庭以及母親工作與否之資訊並無缺失之兒童為研究樣本。研究主要自變項為母親於兒童六個月、十八個月及三歲時是否有工作。中介變項為上述三時期的家庭養育資源，包括母親每天平均陪伴子女的時間，以及每月子女養育總費用。依變項為上述三時期的兒童早期健康與發展，測量指標包括體重、身高、父母親自我評估的兒童發展面向(包括粗動作、精細動作、語言及身邊處理與社會能力發展) 。其他控制變項則包括兒童基本特性、家庭背景、家庭健康以及兒童照護環境。本研究除了利用一般線性迴歸模型及傾向分數分析法控制可觀察的變項外，亦利用長期追蹤統計分析方法試圖控制無法觀察到的變項以解決過去大多數研究未能考慮到的內生性問題。在探討家庭養育資源之中介因子角色時，本研究除了利用階層迴歸分析外，亦使用Baron和Kenny所提出的中介因子及Sobel檢定與Bootstrapping方法進行中介效果之檢定，期望透過這些分析能夠在有更大樣本之資料可使用時，提供未來做更深入研究之基礎。
結果：
根據傾向分數配對法之分析結果顯示，除了在身邊處理與社會能力發展面向，本研究有發現正向平均處理效果外，母親於子女六個月時工作與否對子女六個月及三歲之健康與發展的平均處理效果為負，唯其平均處理效果並沒有達到統計顯著的意義。利用固定效果模型分析發現母親工作與早期兒童健康與發展有統計顯著相關，唯根據隨機截距模型分析則是發現母親工作與幼兒體重有負向關係。在中介效果分析方面，根據固定效果模型中階層迴歸分析結果顯示，每月養育子女費用與幼兒精細動作發展有正向關係，而母親陪伴子女的時間則與幼兒語言溝通發展有正向關係。若利用Baron和Kenny中介效果分析方法，本研究利用時間遞延模型分析養育資源中介效果後發現，母親於幼兒六個月時期工作會透過十八個月養育子女費用而影響幼兒三歲時的精細動作發展。最後，本研究亦發現幼兒出生時的健康狀況與家庭健康對兒童早期健康與發展扮演相當重要的角色。
結論：
母親工作不僅增加家庭的收入，影響了家戶中養育子女的資源配置，同時亦減少母親陪伴其子女之時間與互動之機會。這兩種機制的作用下，母親工作對於幼兒早期健康與發展的影響可能因為正負抵銷而導致本研究之結果並沒有觀察到母親工作對兒童早期健康與發展有統計顯著的影響。未來要增進兒童早期健康與發展應致力於改善兒童出生狀況的健康差距，以及採用以家庭為單位的策略來改善家庭及兒童照護環境。未來研究則可以繼續深入探討個人的選擇與資源的限制所造成的經濟及社會層面的影響，而這些影響亦將個人、家庭之福祉以及家庭成員之關係。

關鍵字

母親工作 ； 養育資源 ； 兒童早期健康與發展 ； 台灣兒童出生世代調查研究

並列摘要

Background and Objectives: Female labor force participation patterns over the life course have experienced dramatic changes in the past several decades. One of the issues surrounding these changes is whether a mother’s employment activities influence the well-being of her children. To date, previous studies have not come to a consensus on how or why a mother’s employment might influence early childhood health and development. Applying family health production theory and the bargaining model in household resource distribution theory, this study investigated the possible direct and mediating effect of mothers’ employment and child-rearing resources on the early health and development of their babies.

Methods: This study utilized the data collected from the Taiwan Birth Cohort Pilot Study. Although the study was a pilot study, it had a representative sample of 2,048 babies born in 2003 which it followed up for three years administering surveys when the babies were 6 months, 18 months, and three years old. This study included only the data on the 1,401 children in that survey who belonged to two-parent families. The key independent variable is whether the mother was working when the child was 6 months, 18 months, and three years old. The mediating factors are child-rearing resources including average number of hours the mother spent with her child daily and total monthly child-rearing expenditures. The early childhood health and development outcomes included children’s weight, height, and four dimensions of parent self-evaluated baby development milestone (gross motor, fine motor, language and social skills). In the model, we also controlled for characteristics of children, family socioeconomic background, family health, and child care environment.
The data were analyzed by traditional OLS model and propensity score matching to control for observable variables as well as longitudinal data analysis techniques to control for unobservable variables to overcome endogeniety problems that most previous studies did not take into account. When investigating the possible mediating role of family child-rearing resources, this study used hierarchical modeling, Baron & Kenny’s strategy supplemented with Sobel test, and bootstrapping to help shed light on the future work when the larger data set is available.

Results: The result of the propensity score matching analysis showed that early maternal employment had a slightly negative average treatment effect but statistically insignificant effect on child health and development outcomes at six months and also at three years except for social skills on which we found that the average treatment effect of maternal employment was positive. After controlling for unobservable variables using fixed effect modeling, maternal employment was not found to have a significant effect on early child health and development, although the results of our random effect model suggested that maternal employment had a negative effect on babies’ weight. Regarding the mediation analysis, hierarchical modeling in our fixed-effect model revealed that monthly child-rearing expenditures had a positive effect on fine motor development and mothers’ time with their children had a positive effect on children’s language development. Based on mediation analaysis proposed by Baron and Kenny, using simple time-lag mediation model testing, we found that child-rearing expenditures at baby’s 18 months old played an important mediating role between maternal employment at baby’s 3 month old and fine motor development at baby’s 3 years old. Finally, this study also found that other factors such as child endowment and family health played an important role in shaping early childhood health and development.

Conclusions: Maternal employment not only brings in the income to the family and reshapes the resource allocation in child rearing within the household but also reduces mothers’ time and interactions with their children. Therefore, the effect of maternal employment on child well-being from these two mechanisms might be canceled out which possibly explain why we did not observe any statistically significant effect in this study. Policies aiming to improve early childhood health and development should focus more on how to reduce the health disparity of new-borns and adopt a family-based approach to improve family health and child care environment. Future research can further develop analyses of the economic and social consequences of choices and resource constraints that ultimately determine the health and well-being of individuals and families, as well as family relationships.

並列關鍵字

Maternal employment ； child-rearing resources ； early childhood health and development ； Taiwan birth cohort study (TBCS)

參考文獻

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