Heterogeneous Labor and Agglomeration over Generations

都市形成の一因として、さまざまな地域から異質な労働者が集まることで生産性が向上することが指摘される。しかし長期的には、労働者が一都市に集中し続けることで労働者の異質性が失われ、次第に生産性が低下することが懸念される。本研究では、労働力の多様性に関する集積の経済と集積の不経済に着目することで、労働者の居住選択と世代交代を通じた都市集積について分析を行う。2地域非重複世代モデルを用いた分析の結果、以下の結論を得た。(i) 労働者の居住分布は短期的には分散化するが、世代交代を経て出生分布は集中化構造に収束する。(ii) 社会厚生は出生分布が分散化したときに最大化される。(iii) 分散力としての住宅消費を考慮した場合、定常状態において出生分布が分散化し、社会的最適が達成されうる。(iv) 労働量に関する集積の経済を考慮した場合、出生分布は社会的最適と比較して過度な集中化をもたらす。

The productivity in cities is enhanced by the interaction between heterogeneous workers who are born and raised in various regions and countries. However, such benefit does not last forever because the composition of workers in cities becomes homogenized over generations. To evaluate the agglomeration economies and diseconomies of labor heterogeneity, this paper constructs a two-region non-overlapping generations model. Workers are assumed to be differentiated in terms of their birthplaces. Although they may migrate from their home regions to other regions to work as foreigners, they should incur an adjustment cost due to cultural differences. Assuming that the distribution of workers' births depends on their previous generation's residency choices, this study obtained the following results: (i) In the short run, residency choice leads workers to disperse across regions in each period. In the long run, however, the accumulation of residency choices over time makes birth distributions concentrated in a single region. Consequently, the composition of the workers becomes homogenized and they continue to reside in one region in a steady-state equilibrium. (ii) Social welfare is maximized by an even distribution of births involving a persistent circulation of heterogeneous labor. A comparison between the social optimum and the steady-state equilibrium indicates a dynamic inefficiency due to generational transition. (iii) When housing consumption is introduced as a dispersion force, social welfare can be maximized in a steady-state equilibrium with an equal distribution. (iv) Contrarily, even when another agglomeration economy is introduced on account of the quantity of labor, distribution of births in a steady-state equilibrium is still concentrated in comparison to the social optimum.

Published: Ihara, Ryusuke, 2019. "Heterogeneous labor and agglomeration over generations," Regional Science and Urban Economics, Vol. 77, pp. 367-381
https://www.sciencedirect.com/science/article/pii/S0166046218301935