Interregional Spillover Effects in the Formation of Metropolitan Growth Centers: Evidence from Gerbangkertasusila Plus
Rizqyansyah- Rizka Firstiani- Muhammad Ichsan

Economics and Development Department, Faculty of Economics and Business, Tadulako University

Abstract

The development of the Gerbangkertasusila Plus metropolitan region represents a strategic initiative to enhance regional economic competitiveness in East Java Province, Indonesia. However, the spatial dynamics and functional linkages among constituent areas remain insufficiently understood, particularly regarding the magnitude and direction of spillover effects from core to peripheral zones. This study examines the spatial spillover patterns and the formation of metropolitan growth centers in Gerbangkertasusila Plus by integrating a gravity model, spatial spillover analysis and moran^s index techniques over the period 2017-2024. The dataset includes per capita GRDP, population, interregional distance, and economic growth rates across the involved districts and municipalities. The analysis identifies Surabaya as the dominant metropolitan core with the strongest economic attraction, generating significant positive spillovers toward Sidoarjo and Gresik, while other surrounding regions exhibit relatively weaker linkages, with some areas showing indications of backwash effects. These findings underscore the necessity of strengthening connectivity, spatial integration, and intergovernmental collaboration to promote a more balanced and sustainable metropolitan growth structure within Gerbangkertasusila Plus.

Keywords: Interregional Spillover Effect, Spatial Interaction, Metropolitan Growth Center

Topic: Economics and Development Planning