| With the globalisation of the economy and the development of information technology,the level of economic development of countries around the world has increased significantly,which has given new impetus to the development of trade in services.At the same time,as the negotiations on the multilateral trading system led by the World Trade Organization(WTO)have not made much substantive progress,countries,out of their own interests,have shifted their vision to conclude regional trade organisations one after another,realising a higher level of trade opening in the region through the signing of Regional Trade Agreement(RTA),and gradually incorporating provisions on trade in services into them,with the number of Regional Trade in Services Agreement(RSTA)The number of RSTA is also gradually increasing.According to WTO statistics,the number of RTA signed and in force worldwide has increased from 28 in 1990 to 579 in 2022,and the number of RSTA has increased from 22 in 1990 to 354 in 2022.In just two decades,the number of RTA and RSTA has grown by leaps and bounds,and the trend of regional economic integration is profoundly influencing the changes in the world economic landscape.Therefore,in this context,it is of some significance to explore the impact of the depth of RSTA on the scale of services trade exports.Focusing on foreign policy,this paper first explores the RSTA and the depth of its provisions and the development dynamics of services trade exports from a worldwide and Chinese perspective,respectively,for a characteristic factual analysis.The paper then elaborates on the theory of regional economic integration and analyses the mechanism by which the expansion of the depth of the RSTA is conducive to the development of services exports,while also exploring the moderating role of services trade costs on the relationship between the two and formulating separate hypotheses.Further,based on DESTA database,combined with UNCTAD,UNComtrade,World Bank WDI and CEPII databases,this paper empirically tests whether the depth of RSTA provisions will have a positive impact on service trade exports,using bilateral service trade export panel data from 37 countries(regions)from 2008-2016 as the research sample.On this basis,it is also explored whether there is heterogeneity in this impact by different types of economies and different specific clause depths.Subsequently,the moderating variable of cost of trade in services is introduced to test whether it can moderate the above effects in order to further refine the relevant theory and research.The results of the study show that the expansion of the depth of the RSTA has a significant effect on the value of services exports of the Contracting Parties;this effect is heterogeneous for different combinations of economies and different specific provisions,i.e.the expansion of the depth of the RSTA provisions brings greater benefits to services exports between developed and developing economies;the promotion of services exports by the expansion of the depth of the provisions under consideration is more prominent.With the introduction of trade costs as a moderating variable,the boosting effect of RSTA depth on the size of bilateral trade in services is found to be weakened.Finally,the paper combines the empirical results to make recommendations:pay attention to the heterogeneity of RSTA provisions,focus on specific depths and build a new pattern of regional services trade opening;pay attention to the development of emerging service industries and improve the problem of unbalanced industry structure;strengthen international cooperation with trading partners to achieve all-round regulation;improve the negotiation discourse and upgrade and improve the relevant provisions of existing agreements. |