Abstract: Building a new development pattern plays a significant guiding role in promoting the construction of a unified national market. Under the new development pattern, due to the relatively surplus characteristics of economic operation, insufficient demand becomes the main constraint on the endogenous growth of the unified national market. The demand-side expansion will lead to industrial agglomeration, which in turn will further stimulate the supply-side growth, promoting a spiral rise in demand and supply and facilitating the formation of the high-level supply-demand circulation system in the domestic market. This indicates that the essence of the endogenous growth logic of the unified national market under the new development pattern is a dynamic process of continuous transition from a low-level to a high-level supply-demand circulation system based on the principle of demand creates supply. It can be explained by the circular cumulative causality mechanism. The source driving mechanism based on the home market effect explains the inducing effect of demand expansion on industrial agglomeration, while the circular driving mechanism based on the localized knowledge spillover effect explains the promoting effect of industrial agglomeration on supply growth. Therefore, the policy focus for the construction of a unified national market under the new development pattern should be placed on the demand-side management, initiating a high-level domestic circulation under the logic of demand creates supply through expanding domestic demand, and promoting the endogenous growth of the domestic market from being large to being strong.
