北京市汽車限購政策的外溢效果

Abstract

隨著中國經濟快速發展，城市的汽車保有量快速成長，但也導致交通擁堵、空氣汙染、能源短缺的問題日益嚴重。北京市於2010年12月23日公佈汽車限購政策，希望透過控制汽車總量的方式，減緩汽車增加的速度。但由於在北京購車需先透過搖號方式獲得車牌，其中籤率很低，因此北京居民可能到鄰近城市購買汽車並註冊車牌，而產生政策外溢效果，降低政策的有效性。因此本文使用雙重差分法進行估計，研究北京市在實施汽車限購政策後，政策對於鄰近城市汽車銷售量的影響，以觀察政策的外溢效果。\n本文之資料來源為中國月度新車登錄資料，樣本資料期間為2009年1月至2012年12月。依照與北京距離遠近區分實驗組與控制組，距離北京較近的縣為實驗組，距離北京較遠的縣為控制組。實證結果顯示，在汽車限購政策實施後，距離北京較近的縣相對於距離北京較遠的縣，汽車銷售量顯著增加，且隨著與北京的距離越近，其效果越大，因此存在著政策的外溢效果。

With the rapid economic growth in China, automobile ownership and use has increased over the past decades. However, it led to exacerbated traffic congestion, worsened air pollution, and energy consumption, these problems have become increasingly serious. Therefore, Beijing government adopted Automobile Purchase Restriction Policy in December 23,2010, hoping through the policy it could constrain the quantity of automobiles, and decrease the growth rate of automobiles. However, Beijing employs lottery policy with low winning rate, it causes that residents may purchase and register their cars in neighboring cities, and the spillover effect may reduce the policy’s effectiveness. Therefore, this article uses Difference-in-Differences method to analyze how the sales of neighboring cities would be affected after the Automobile Purchase Restriction Policy, and this article aims to explore the spillover effect.\nData used in this article is from Monthly Increase in Registered Vehicles Across China. During the period from January 2009 to December 2012, we set the neighboring districts as an experimental group and the far districts as a control group. The empirical results show that after the Automobile Purchase Restriction Policy, the sales of automobiles significantly increase by compared neighboring districts and far districts. As the distance gets nearer, the sales of automobiles have a significant positive impact. The results reveal that the Automobile Purchase Restriction Policy has the spillover effect to the neighboring areas.