E-Marketplace Competition and Digital Economic Sustainability in Thailand: An Oligopoly Analysis with Policy Benchmarking from ASEAN Countries

Abstract

This study examines the competitive structure and economic effects of Thailand's E-Marketplace, using the Structure-Conduct-Performance (SCP) framework as the primary analytical framework, supported by Two-sided Market Theory, Transaction Cost Theory, and Platform Economy concepts. The analysis shows that Thailand's E-Marketplace market is oligopolistic, dominated by foreign platforms that hold about 95–100% of the market. This results in two economic effects: positive impacts, such as increased consumer surplus, creation of digital jobs, and cross-border export opportunities for SMEs via E-commerce; and negative impacts, including risks of market dominance, fee hikes, barriers to entry, concerns over imported product quality, unfair competition, and issues related to technology dependence and data security. The study also conducts a policy benchmarking analysis across four ASEAN countries—Indonesia, Vietnam, Malaysia, and the Philippines— chosen through policy diversity criteria and purposive sampling. Based on these findings and the broader SCP analysis, five policy recommendations are proposed to enhance Thailand’s sustainable cross-border digital trade and its participation in the ASEAN Digital Economy Framework Agreement (DEFA): imposing import taxes on small-parcel trade; regulating platform market dominance and unilateral fee increases; establishing an Online Sellers Association; regulating platform data usage and algorithm transparency, including Data Localization considerations; and supporting Thai SMEs in accessing AI tools, digital marketing, and content creation on global platforms, using E-Marketplace as an export channel.