【摘要】The concept of agglomeration economies as determinants of industrial clustering has a long history in urban economics. Most writers, of course, argue that transportation economies constitute the primary explanation for the concentration of activities in cities. But the importance of agglomeration effects is frequently mentioned. Although the dictionary treats agglomeration as a virtual synonym for clustering, the term seems to carry a heavier, if amorphous, burden in economists’ writings on location and industrial organization. Clustering, as they note, certainly lowers the cost of doing business for certain firms in certain locations (although it may well raise the costs for others) but such direct cost reductions appear to us an unsatisfying explanation for the amount of agglomeration one actually observes. Neither does limiting the agglomeration notion to external economies illuminate declustering phenomena, i.e., the flight by firms from the center of large old cities.Writers point to three sorts of external economies which agglomeration attempts to exploit.

【文献来源】Pascal A H, Mccall J J. Agglomeration economies, search costs, and industrial location[J]. Journal of Urban Economics, 1980, 8(3):383-388.