An Analysis of Dynamic Changes in Sales by Local Currency Franchise Categories Using Latent Growth Model

This study empirically examines the impact of SIRU, the local currency of Siheung City, on local economic revitalization using merchant transaction data. Unlike previous studies that primarily relied on perception-based surveys, this research utilizes actual transaction-level data and applies a Latent Growth Model (LGM) to analyze category-level sales changes between 2022 and 2024. The results indicate that SIRU effectively channels consumption toward neighborhood businesses such as small retailers, restaurants, and educational services, while also promoting digital transformation by reducing transaction costs through mobile QR payments. Notably, sales across merchant categories exhibited significant temporal dynamics, with categories that had larger initial sales volumes showing relatively sharper declines. These findings suggest that local currency policies should prioritize differentiated support for sectors with higher growth potential rather than uniform issuance expansion. The study also discusses several limitations, including incomplete metadata management, lack of appropriate comparison group data, and insufficient control for exogenous factors, and highlights the need for future research to apply non-linear models and improve data governance for more precise evaluation. Finally, the study offers policy implications, recommending sector-specific incentive schemes, enhanced support for digital transition, the establishment of data-driven performance monitoring systems, and the development of sustainable public private collaboration models for local currency management.