聚集经济研究到单个城市这一层次,就基本上没有再向前拓展了。实际上,个体城市之间也有聚集动力。聚集经济除了企业内部聚集经济、行业内部聚集经济、城市聚集经济三个层次以外,还应当向城市外部拓展,形成第四个层次——空间聚集经济,这对于解释城市群的形成与发展机制具有重要意义。 Agglomeration economic studies to a single city at this level, basically no longer move forward. In fact, individual cities also gather momentum. Agglomeration economy should be expanded to the outside of the city to form the fourth level, the space-gathering economy, which explains the formation and development mechanism of the urban agglomeration in addition to the internal agglomeration economy within the enterprise, the internal agglomeration economy within the industry and the urban agglomeration economy. Significance.