中國經濟發展快速的情況下，人民對於汽車的需求也一直再提高，在基礎建設尚未追上汽車數量增加之下，道路擁擠與環境汙染成為了許多城市必須面對的問題。北京市政府於2010年12月23日實施汽車限購政策，希望透過此政策降低汽車增加的速度。另一方面，中國將發展汽車自主品牌作為重要政策之一，希望藉由外資的技術讓自主品牌的汽車打入國際。因此本文將使用差中差法進行估計，研究北京市在汽車限購政策之後，政策對於自主品牌銷售的影響。 研究中所使用的資料為中國「中國車輛登記管理所」之中的「全中國登錄各月新增車輛」，加上「易車網」的汽車特性資料整理而成。以北京市的自主品牌車系作為實驗組，非自主品牌車系作為對照組進行多次估計，其中包括加入時間趨勢及將極端樣本去除等。研究結果皆顯示，在汽車限購政策後，確實對於自主品牌汽車銷售有下降的影響，最後也加入了穩定性檢驗，證明自主品牌的銷售下降是否與政策有關。最後結果亦與預期相同，證實北京市的汽車限購政策對於自主品牌的銷售有負向的效果。 / With the rapid economic growth in China, people’s demand for automobiles has risen continuously during the past decades. Furthermore, because the infrastructure in China failed to sustain the increase in the quantity of automobiles, traffic congestion and environmental pollution are the problems many cities have to be confronted with. Therefore, Beijing government adopted Automobile Purchase Limit Policy in Dec. 23, 2010, hoping that through the policy it can decrease the growth rate of automobiles. On top of that, developing self-owned Brand for automobiles in China is its primary policy, China government hoped to take advantage of foreign technology to make its self-owned Brand step into the international market. Consequently, this article uses Difference-in-Difference method to analyze how the sales of self-owned brand automobiles would be affected after the Automobile Purchase Limit Policy was enacted. Data used in this article is from Monthly Increase in Registered Vehicles Across China, which is from Vehicle Registration and Managemet Bureau of Chian, and from Yiche Network. Setting the self-owned brand mobiles in Beijing city as an experimental group and non-self-owned brand mobiles as a control group, we are to estimate many times. We try to take time series effect into account and eliminate outlier samples. The result shows that after the Automobile Purchase Limit Policy, the sales of self-owned brand automobiles significantly decrease. Finally, we add stability test to observe whether the decrease in the sales of self-owned brand automobiles is related to the policy or not. The result reveals that the Automobile Purchase Limit Policy in Beijing has a negative impact on the sales of self-owned brand automobiles.

北京市為解決嚴重的道路堵塞問題，自2010年12月23日實施汽車限購政策。北京市於2010年10月傳出將要實施汽車限購政策，而本研究使用差中差方法估計消息傳出至開始實施日期間，政策消息對於汽車銷售量之影響。 研究中所使用之汽車銷售資料來源為中國「車輛登記管理所」中的「全中國登錄各月新增車輛」，以及「太平洋汽車網」的汽車詳細特性資料整理而成。以北京市為實驗組，其他非北京城市，與重慶市、天津市等為對照組，在控制了汽車特性以及加入了時間趨勢之後，可從實證結果得知，不論是以哪些城市當作對照組，在這段期間內，北京市的汽車銷售量皆有顯著的增加，與預測的結果相符。 在研究最後進一步使用穩定性檢驗，證明北京市汽車銷售量的突然增加是否真的為政策消息影響。最後結果亦與預期相符，證實北京市的汽車銷售量突然增加是由汽車限購政策消息所影響。 / To solve the serious road congestion problems, Beijing has implemented the restrictions on car ownership. In October, 2010, news started to spread that Beijing would bring the automobile purchase limit policy into practice. This study, using a method named “difference-in-difference”, estimated the policy’s impact on automobile sales volume in the period from when the news was launched to the day the policy was actually implemented. The data in this paper come from “Monthly Increase in Registered Vehicles Across China” of “Vehicle Registration and Management Bureau of China”, and the detailed characteristic data of vehicles from “Pacific Automobile Network”. We set Beijing as the experimental group, and the non-Beijing cities such as Chongqing and Tianjin as the control group. After controlling the characteristics of vehicles and adding time trend, we can learn from the experimental result that no matter which city is used as the control group, during the period, the vehicle sales volumes in Beijing increase significantly, which meets our expectation. In the last step of the research, stability test is used to prove whether the sudden increase of Beijing’s automobile sales volume is affected by the spread news. And the final result is also in accord with our expectation: the sudden increase in Beijing’s automobile sales volume is affected by the spread news of the automobile purchase limit policy.