中小学生学业负担过重问题一直是一个被广泛关注的话题，尤其是近年来引起了社会各界的高度重视。尽管各级政府和教育行政部门出台了减负增效的相关政策，但教育生产过程中的时间效率评估和价值分析还相对缺乏。时间资源具有较大的价值，是一种可以获得未来预期收益的资本。时间分配反映了个人的潜在偏好，时间的分配和管理对学生的发展有着重要影响。因此，从预期收益的角度考察学生课外活动时间，帮助其合理分配课外活动时间，提高时间管理的效率就显得尤为重要。本研究基于教育生产函数理论模型和时间分配理论对初中生课外活动时间分配进行研究，有助于政府、学校和家长了解学生课外活动时间分配的基本情况，进而为引导学生合理规划和安排学习和闲暇时间，提高学习效率、减轻学业负担、促进学生全面发展提供决策参考。 本研究利用中国教育追踪调查2013-2014学年基线调查数据，通过定量研究方法，对初中生课外活动时间分配问题进行较为全面、系统的分析。首先，利用描述性统计对初中生各类课外活动时间分布以及不同特征学生在课外活动时间分配差异进行分析。其次，运用多层线性模型，对我国初中生课外活动时间分配影响因素进行分析。最后，利用多层线性模型和结构方程模型，探究初中生课外活动时间分配与学业成绩的关系。综合以上分析，本研究得出以下主要研究结论： 一、我国初中生学业负担偏重，课外活动时间分配比例失调。一方面，初中生课外学习时间偏多，超出了国家相关政策的限定；另一方面，初中生课外闲暇时间偏少，低于国家相关政策的限定。调查显示，50%以上的初中生作业时间在2小时及以上，三分之二左右的学生体育运动时间达不到1小时，将近80%的初中生睡眠时间不足9小时。 二、认知能力较强、家庭背景较好以及城市学生的课外学习时间更长。时间作为一种资本，学生在学习时间上投入更多，可以获得更高的成绩收益。认知能力较强的初中生学习效率较高，同时在课外学习时间投入更多，拉大了与认知能力较差学生的学业差距。家庭背景较好以及城市学生更易获得优质教育资源，同时他们在课外学习上投入了更多时间，拉大了与家庭背景较差和乡镇农村学生之间的学业差距。 三、初中生课外活动时间与学业成绩大多呈现倒U型关系。减负政策的实施使得学生的课外活动时间增多，弱化了学校教育的功能，增强了课外活动对学生学业成绩的影响。根据卡罗尔的学校学习模型，各类课外活动的“实用时间”和“需用时间”较为一致时，学生才能获得最高的学习效率。因此，无论是学校和教师还是家长和学生都应该根据学生自身情况，合理地管理和分配学生课外活动时间，提高学生综合素养，促进学生全面发展。 四、家庭背景通过影响学生课外活动时间分配，进而影响学生学业成绩。家庭背景对学生课外活动时间分配有着显著影响。学生差异化的课外活动时间是由家庭背景的差异所引起的。家庭背景在学生课外活动时间分配中起着重要的支配和掌控作用，从而不断地渗透到学生发展当中，并加大了不同家庭之间的教育差距，体现了社会再生产功能，不利于社会流动。 基于本文研究结论提出如下建议：第一，科学合理布置作业，提升作业品质。第二，理性对待课外补习，加强家校合作，共同为学生减负。第三，合理利用和分配学生课外活动时间，提高学生综合素养。第四，鼓励学生开展课外阅读，提升学生阅读素养。第五，加强体育运动，促进学生体质健康。第六，合理安排娱乐时间，科学使用电子设备。第七，重视劳动教育，建构学生劳动教育实践体系。第八，保证学生睡眠时间，促进学生身心健康发展。 本研究的贡献主要体现在研究方法和研究内容两方面。采用多层线性模型和结构方程模型，对初中生课外活动时间分配进行分析，构建课外活动时间分配与学生学业成绩的模型，丰富和改进了国内教育生产函数理论模型，为后续研究方法提供了借鉴。基于实证结果给出的相关研究结论和政策建议为各级教育行政部门、学校和教师、家长和学生合理安排学生课外活动时间，减轻学生学业负担提供了有益参考。

The topic of overburdened schoolwork of primary and secondary school students has always been widespread concerned. Especially in recent years, it has attracted great attention from the social community. Although governments and Educational Administrative Departments at all levels have issued several policies to reduce burdens and increase efficiency, there is still a relative lack of time efficiency evaluation and value analysis in the process of education production. Time is a resource that has great value and it’s a kind of capital that can obtain income in the future. The allocation of time reflects the individual's potential preferences, and the allocation and management of time have an important impact on students' development. Therefore, from the perspective of expected return, it is vital importance to help students allocate extracurricular activities reasonably and improve the efficiency of time management. Based on the theory of Education Production Function and Allocation of Time, this paper studies the time allocation of extracurricular activities of middle school students. It is helpful for the government, schools and parents to understand the basic situation of the time allocation of extracurricular activities, and then provide decision-making reference for guiding students to plan and arrange their study and leisure time rationally, improving learning efficiency, reducing burden and promoting students' all-round development. Based on the baseline survey data of China Education Panel Survey from 2013 to 2014, the research makes a comprehensive and systematic analysis of the time allocation of extracurricular activities for middle school students through quantitative research methods. Firstly, descriptive statistics are used to analyze the time allocatioan of extracurricular activities of middle school students and the differences of time allicatioan of extracurricular activities among students with different characteristics. Secondly, the research uses Hierarchical Linear Model to analyze the factors that influence the time allocatioan of extracurricular activities of middle school students. Finally, Using Hierarchical Linear Model and Structural Equation Modeling, this research explores the relationship between time allocation of extracurricular activity and academic performance of middle school students. Furthermore, it explores the time allocation schemes of extracurricular activity of students with different characteristics. Based on the above empirical research results, the main conclusions are as follows: 1. The burden of middle school students is heavy and the proportion of time allocation of extracurricular activities is imbalanced. On one hand, middle school students have more extracurricular study time, which is beyond the limits of relevant national policies. On the other hand, middle school students have less extracurricular leisure time, which is lower than the limits of relevant national policies. According to the research, more than fifty percent of middle school students do the homework for two hours or more, and about two-thirds of students have less than one hour for physical activity, and nearly eighty percent of them sleep for less than 9 hours. 2. Students with higher cognitive ability, better family background and living in urban areas have longer extracurricular learning time. As a kind of capital, students can invest more in their study time and get higher achievement. The middle school students with higher cognitive ability have higher learning efficiency, and they have more extracurricular learning time, which enlarges the academic gap between them and those with lower cognitive ability. The students with better family background and living in urban areas can get quality educational resources easily. And at the same time, they devote more time to extracurricular study, which enlarges the academic gap between students with poor family background and living in towns and villages. 3. The relationship between extracurricular activities and academic performance show inverted U-shaped. The implementation of the burden-reduction policy has increased the time for extracurricular activities of students, which weakens the function of school education, and enhances the influence of extracurricular activities on students'academic performance. According to Carroll’s model of school learning, students can achieve the highest learning efficiency when “the time available to learn” and “the time need to learn” of various extracurricular activities are consistent. Therefore, no matter schools and teachers as well as parents and students should manage and allocate their extracurricular activities according to their own situation in order to promote and improve their comprehensive quality. 4. The family background affects students' academic performance by affecting the allocation of extracurricular activities time. Family background has a significant impact on the time allocation of extracurricular activities. The difference of students' extracurricular activity is caused by the difference of family background. Family background plays an important role in mastering and allocating the time of extracurricular activities. As a result, it constantly penetrates into the development of students and deepens the educational gap between different families, which reflects the function of social reproduction and is not conducive to social mobility. Based on the above conclusions, this study puts forward the following suggestions: First, arranging homework scientifically and rationally, improving the quality of homework. Second, treating extracurricular tutoring rationally and strengthening home-school cooperation to reduce the burden of students. Third, using and allocating the time of student extracurricular activities rationally, improving students' comprehensive quality. Fourth, encouraging students to do outside reading to improve students' reading literacy. Fifth, strengthening the physical activity of students to promote students' physical health. Sixth, arranging entertainment time reasonably, using digital devices scientifically. Seventh, attaching importance to labor education amd constructing the practical system of student labor education. Eighth, guaranteeing the sleep time to promote the physical and mental development of students. The contribution of this research mainly embodies in aspects of methods and contents. Using Hierarchical Linear Model and Structural Equation Modeling, this research analysis the time allocation of extracurricular activities for middle school students and constructs a model of time allocation of extracurricular activities and student academic achievement. This research will enrich domestic studies in education production function and take the lead in the research of this area. The empirical research findings and the related policy suggestions could be useful for governments, schools, teachers, parents and students to allocate the time of students’ extracurricular activities and reduce students’ burden.