本文从创新型城市试点建设的视角检验“以点带面”这一中国特色改革举措产生作用的过程与机理。以创新型城市试点建设为准自然实验，构建双重差分模型，检验该政策的实施对邻近城市创新活动的影响。研究发现：①创新型城市试点建设对邻近城市产生了“示范效应”，提升了其创新水平；“示范效应”具有空间差异性，东部地区最大；“示范效应”具有动态波动性，随时间变迁起伏变化。②“示范效应”具有城市异质性，在不同邻近距离、不同等级城市间均表现不同。③创新型城市试点建设通过政府政策制定的邻里效应和促进试点邻近城市创新要素集聚共同产生影响。本文的研究一方面为创新型城市试点建设的综合评价提供了新视角，另一方面也为政策措施的改进提供了思路。

    Construction of pilot projects is a policy making process with Chinese characteristics. From the perspective of innovative-city construction, this paper examines whether there is "point to area" effect in the process of implementing pilot projects and further analyzes its mechanism. Innovative-city construction is an important measure to build innovative country and realize the innovation-driven development strategy. In 2008, Shenzhen was approved as the first national innovative-city pilot area. Then in 2010, the Ministry of Science and Technology issued "Notice on Promoting the National Innovative-city Pilot Work", identifying Dalian, Qingdao and other 16 cities as the national innovative-city pilot areas. By 2019, the number of national innovative-city pilot area reached 78. In terms of implementation process, this is a typical Chinese experience of "pilot-extended-demonstration". However, few empirical studies focused on the effect of innovative-city construction, especially the demonstration effect of innovative-city construction.  
    In China, pilot policies usually have two political missions. On the one hand, pilot project construction is a summary of experience. In the policy formulation process, local governments of pilot cities are encouraged to try various solutions to problems based on local characteristics, and feedback the experience to the central government. On the other hand, pilot project construction is supposed to produce a demonstration effect. The typical successful experience of the pilot area is promoted through media reports, experience exchange meetings, visits and learning activities, so that other regions imitate them, thereby producing the effect of "point to area".
    However, pilot cities usually receive policy incentives from the central and other levels of government, they may also trigger the accumulation of resources from other regions, especially neighboring cities. As a result, pilot cities will have a negative impact on the innovation of neighboring cities, presenting the so-called "siphon effect". Based on this, this research attempts to answer the following questions: Does the pilot city have an impact on the innovation of neighboring cities? Is this effect a demonstration effect? Is it continuous? Is it heterogeneity with urban characteristics? What are the paths?  
    Using the panel data of 266 cities at or above prefecture-level from 2003 to 2016, we evaluate the effect produced by the innovative-city construction pilot project. In order to control possible problems of sample self-selection, we use the propensity score matching method (PSM) to process the samples. Then, a double difference model (DID) is employed to evaluate the "pilot effect" and its dynamic evolution, and a triple difference model (DDD) is constructed to test heterogeneity. Further study examines the policy diffusion path and factor flow path from the perspective of peer effect and factor agglomeration. 
    The findings are as follows: (1) Innovative-city construction has a demonstration effect, which significantly improves the innovation level of neighboring cities. The effect is the largest in the east and the smallest in the west. Furthermore, the effect is persistent and reaches a peak in the third year after the pilot. (2) The demonstration effect is heterogeneous with urban characteristics, it is more significant among cities that are not geographically connected to the pilot cities, and cities at sub-provincial level or above. (3) Innovative-city construction acts on neighboring cities through the neighborhood effect of government innovation policy and promoting the agglomeration of innovation elements in neighboring cities.  
  The policy implications of this study include: (1) The government should continue to expand the scale of innovative-city construction and promote the orderly diffusion of innovative city. In the process of layout of innovative cities, the positive externality of innovative city construction should be considered. The comprehensive strategic layout of innovative cities should be carried out from multiple angles such as geographical location and city level. (2) In order to achieve a more positive demonstration effect, the policy diffusion path should be fully utilized. It is necessary to sum up the experience and achievement of innovative city construction in time. At the same time, advanced experience should be promoted through a variety of channels to expand the influence. (3) Regional interaction should be strengthened and collaborative innovation should be encouraged. The interconnection of innovation elements should be fully considered when a series of supporting measures are taken to construct innovative cities. Regional cooperation networks should be actively formed to achieve a win-win result.