人口聚集型態與經濟成長

Abstract

經濟活動的聚集對經濟成長的影響，可能隨著經濟成長的階段與型態的不同而改變。傳統的都市化人口比率呈現整體聚集經濟的程度，無法反映聚集經濟的差異。本文以估計的等級規模係數衡量都市間人口的差異程度，實證分析不同的聚集變數（都市化人口比例與都市人口差異程度），是否因國民所得與開放程度的不同，對經濟成長有不同的影響。主要貢獻為：（一）以都市化人口比率衡量聚集變數時，本文較Brülhart and Sbergami（2009）多採用2000－2010年資料，估計的門檻值較低，約7,100美元。（二）初探都市間規模差距對經濟成長的影響，較都市化人口比率變數更為顯著且結果不同。所得成長率可能隨著都市規模差異的縮減而降低，而其降低的幅度會隨著所得水準的增加而增加。都市政策宜考慮都市絕對規模與都市間相對規模。

The effect of spatial concentration and hierarchy of economic activity on national growth is investigated using cross-section OLS and dynamic panel GMM estimation. Agglomeration patterns are measured by urbanization shares and level of urban hierarchy, which is measured through rank-size coefficient. We find evidence supports the "Williamson hypothesis" however, the critical level is estimated at USD 7,100 lower than that of previous work. The impact of the level of urban hierarchy on country level growth is significant and positively related to national income. This result implies that not only the degree of absolute agglomeration effect but also the relative size of agglomerations among cities is worth considering.