Abstract:Digital technology provides new opportunities to resolve the "cost disease" problem in the service industry. In view of the fact that the analysis of the impact mechanism of digital technology on service industry productivity from the perspective of economies of scale and structural modernization effects is lacking, thus, using the Information and Communication Technology (ICT) index provided by the United Nations Conference on Trade and Development (UNCTAD), depicting economies of scale by the level of service trade, while indicating the degree of structural modernization of the service industry by the proportion of the export of high-tech services in the total export of services, this paper uses fixed effect models and intermediary effect models, based on cross-national panel data of 176 economies from 2009 to 2021 from the World Bank database, to test the impact and its mechanism of service industry productivity. Also, an empirical analysis is conducted of differences between high-income economies and low- and middle-income economies. The results find that: digital technology significantly improves the productivity of the service industry, with the reshaping effect of economies of scale and the transformation effect of structural modernization serving as mediating roles; digital technology can significantly improve the productivity of the service industry in high-income economies, while its impact on low- and middle-income economies is not significant. This is possibly caused by the less developed technology in low- and middle-income economies, and the scale and extent of digital technology development fails to take effect. To this end, efforts should be made to develop digital technology, give full play to the economies of scale and structural modernization effects of digital technology, promote the multi-scenario integration of digital technology and the service industry, and strengthen the penetration of digital technology into the service industry.