垃圾分类象征着一个社会的文明程度，已经成为了当代中国社会的新时尚。自2000年起，北京市生活垃圾分类试点政策已经实施了二十年。多年来，北京市各级政府花费了大量的人力、物力、财力，构建起较为完善的生活垃圾分类制度体系，奖励生活垃圾分类行为，诸如免费发放垃圾袋，招募志愿者对生活垃圾分类进行主题宣传，引入生活垃圾分类教育至小学课堂，等等。但从分类效果来看，试点政策成效平平，坚持严格执行生活垃圾分类政策的小区寥寥无几，绝大多数的居民并没有养成将生活垃圾分类的良好习惯，生活垃圾混分、混收、混运的现象依然普遍存在。推行了二十年的生活垃圾分类试点政策收效甚微，北京市生活垃圾分类难题迫在眉睫。当前，学界学者主要将目光聚焦于生活垃圾分类处理阶段的技术难题攻克以及源头分类阶段的政策制定研究。较少有研究将生活垃圾分类视为公共政策的一种，并且选择从政策执行角度研究该政策体系在实际实践中存在的问题并探讨解决对策。因此，从执行层面出发探讨提升北京市生活垃圾分类效果这一课题，成为了当下生活垃圾分类研究的热点。

在对北京市及国内外其他国家和城市生活垃圾分类政策执行文献综述的基础上，本论文选择美国学者T.B.史密斯的“史密斯政策执行过程模型”理论作为分析框架，分别从“史密斯模型”理论的四个组成要素，即，理想化的政策、执行机关、目标群体和环境因素^[1]等，探讨北京市生活垃圾分类政策执行中出现的问题，借鉴国内外生活垃圾分类政策执行经验，希望能对北京市生活垃圾分类政策执行提出建设性的对策建议。本论文使用问卷调查法，以北京市生活垃圾分类相关的政策文件、客观数据和调查问卷数据为基础，研究北京市生活垃圾分类政策执行过程中面临的问题，将问题主要归纳为四类，一是政府制定的生活垃圾分类政策不够明晰，没有统一标准，影响执行成效；二是主管部门职能交叉，强制执行推动不足；三是居民的环保意识淡薄，缺乏较强的自觉进行垃圾分类的意愿，执行效果难以延续；四是监督体系缺失等环境因素的影响。

Waste classification symbolizes the degree of social civilization and has become a new fashion in the contemporary Chinese society. Since 2000, the pilot policy of waste classification in Beijing has been implemented for nearly two decades. Over the years, all levels of governments in Beijing have spent a lot of manpower, material and financial resources to build up a fairly complete waste classification system by rewarding the waste classification behaviors such as granting free waste bags, recruiting volunteers for the waste classification theme propaganda as well as introducing education into primary school classroom and so on. However, from the perspective of classification effect, the pilot policy has almost entered the status of existing in name only. Only a few residential communities adhere to the strict implementation of waste classification policies, and the vast majority of the residents have not developed the good habit of classifying waste. The phenomenon of waste mixed distribution, mixed collection, and mixed transport is still widespread. The pilot policy of waste classification has been carried out for nearly 20 years with little effect. At present, the researches on waste classification policies of domestic and foreign scholars focus more on the technical problems in each stage of waste classification and the formulation of policies. The studies regarding waste classification as a public policy are few, especially the researches that analyze the issues and countermeasures of waste classification from the perspective of policy implementation. Therefore, how to improve the implementation effect of waste classification policies in Beijing has become a hot topic in the contemporary research of waste classification.

On the basis of literature review of waste classification policy implementation at home and abroad, this paper selects the Smith Policy-Implementation Processing Pattern by the American scholar T.B.Smith as the analytical framework. The paper studies the four contents of the Smith Policy-Implementation Processing Pattern, namely, idealized policy, enforcement agencies, target groups and environmental factors^[1]to discuss the issues and causes of waste classification in the policy execution in Beijing, hoping to put forward constructive countermeasures and suggestions in waste classification policy implementation for Beijing.This paper uses the method of questionnaire survey. Based on the related policies, objective data and questionnaire data concerning waste classification in Beijing, the issues in the process of policy implementation of waste classification in Beijing are studied. The issues are summarized into four categories. First, the waste classification policies formulated by the government are not clear, lacking uniform standard for people to follow. Therefore, the effect of execution is not good. Second, the functions of the competent departments are overlapping, leading to insufficient enforcement of the policies. Third, the residents' awareness of environmental protection is weak, and their willingness of waste classification is not strong enough, so the implementation effect is difficult to continue. Fourth, the performance of the implementation is affected by environmental factors such as the lack of supervision system.