Do compact cities have higher efficiencies of agglomeration economies? A dynamic panel model with compactness indicators

Compact development is proposed to preserve land resources as well as promote agglomeration economies. This paper adopts a multi-indicator system of compact cities, including population density, boundary limitation, and road density, to examine the relationship between the compact city and urban efficiency through agglomeration economies. We empirically examine the relationships between compact city indicators and comprehensive/ technical efficiency measures of the cities through GMM regression with panel data of 226 prefectural and upper level cities in China during 2001-2015. We find the answers heterogeneous for each indicator-efficiency pair for each city type. Higher population density and compact urban form are beneficial to the urban economic efficiencies of large cities, but not for the technical efficiency of small cities. Road density is conducive efficiencies for small and medium cities, but not technical efficiencies for large cities. We confer that the heterogeneity may be explained by the economic structure compositions of cities of different sizes. Based on our findings, we propose tailor-made policy suggestions regarding urban compactness and economic efficiencies for cities of different sizes.