sustainability Article Towards Sustainable Urban Spatial Structure: Does Decentralization Reduce Commuting Times? Chunil Kim 1 and Choongik Choi 2,* 1 Housing Urban Finance Institute, Korea Housing & Urban Guarantee Corporation (HUG), BIFC, 40 Munhyeon-geumyung-ro, Nam-gu, Busan 48400, Korea;
[email protected] 2 Department of Public Administration, Kangwon National University, 1, Gangwondaehak-gil, Chuncheon-si, Gangwon-do 24341, Korea * Correspondence:
[email protected]; Tel.: +82-33-250-6813 Received: 31 December 2018; Accepted: 7 February 2019; Published: 15 February 2019 Abstract: This paper contributes to the existing debate on the co-location hypothesis, by devising a proximity measure and controlling for a set of other urban form measures. Utilizing the LEHD (Longitudinal Employer–Household Dynamics) Origin-Destination Employment Statistics (LODES) data that provide the number of jobs by a finer geography, this paper measured the degree of centralization, proximity, and job–housing mismatch. Multiple regression analysis revealed that the job–worker proximity leads to a shorter commuting time. In addition, the results focusing on suburban areas revealed that the impact of the job–worker imbalance and the impact of job–worker mismatch on the commuting time are greater in the suburb in comparison with the city center. Keywords: urban spatial structure; commuting; job–housing ratio; floating catchment area 1. Introduction The evolution of spatial structure plays a significant role in shaping interactions among decision-making agents in cities. The development of transportation technologies transformed old port city centers and connected inland areas to each other. As the railway system came into existence, firms that had been locked in the port center could move along the rail lines.