本研究探討中間區位在NEG模型的隨處資本家(FE)版本與Helpman’s (1998)版本中的角色。考慮包含三區域的兩種空間型態：一為等邊三角形（無中間區位）；另一為一線上的三點且相鄰兩點等距（中點的區位為中間區位）。研究結果顯示這兩種型態會有一些差異。在無中間區位的型態中，在FE模型的低運輸成本以及Helpman模型的高運輸成本時，廠商會聚集於任一區域；而在FE模型的高運輸成本以及Helpman模型的低運輸成本時，廠商會平均分布（分散）在三區域。在具中間區位的型態中，廠商分散（對稱分布）的情況在FE模型運輸成本較高（比較無中間區位）時才會出現，因為此時中間區位的優勢才會消失。但是此種對稱分布在Helpman模型中不會出現，除非運輸成本趨近於0。在Helpman模型中，當運輸成本上升時，一個非對稱分布出現且中間區位的廠商比例由1/3遞增，表示在以住宅為主要離心力的Helpman模型中，中間區位的優勢仍然存在。

This study explores the role of median location in a footloose entrepreneur (FE) version and Helpman’s (1998) version of NEG models. Two kinds of location distribution for three regions are considered: One is an equilateral triangle (with no median location). The other is the distribution in which three points are equidistant between two adjacent points on a line (the middle region is the median region). The results show that there are some differences between these two settings. In the setting with no median location, firms will agglomerate at any of the three regions with low transport costs in the FE model and high transport costs in the Helpman model and will equally distribute among the three regions with high transport costs in the FE model and low transport costs in the Helpman model. In the setting with a median location, the symmetric industrial dispersion among the three regions emerges when transport costs are larger than those in the triangle with no median location in the FE model, because the advantage of median location is lost only when transport costs are larger. However, this symmetric dispersion never emerges in the Helpman model unless transport costs approach zero. In the Helpman model, a unique asymmetric distribution at the median location increases from one-third as transport costs increases. This shows that the advantage of median location exists even in the Helpman model, which provides housing services as a major centrifugal force.