Abstract: The accelerating development of the digital economy has made new infrastructures an important tool to overcome the unevenness of regional resource endowments as well as the imbalance and inadequacy of regional development. However, an important prerequisite for exploring the socio-economic benefits of new infrastructures is to determine how to establish a framework for measuring the stock size of new infrastructures to understand the historical development patterns and spatial distribution characteristics of different types of new infrastructures. This paper combines the capital stock method and the physical quantity method to construct a theoretical framework for measuring the new infrastructure stock, and adopts the kernel density and Dagum's Gini coefficient to estimate the regional heterogeneity and unbalance of new infrastructure in China. The results show that the national capital stock of new infrastructures is in an accelerating growth stage, which sees a widening gap between eastern China and central-western China. Converged infrastructure has surpassed, in scale, information infrastructure since 2009 and become the main driving force for the vigorous development of new infrastructures. The results based on Kernel density estimation show that the spatial unbalance of new infrastructure stock has intensified, as evidenced by starker scale difference between eastern China and central China, and the intra-regional Gini coefficient in western China has risen sharply despite the rapid growth in the scale of local new infrastructures. In addition, inter-regional development gap is still the main reason for the inter-regional differences of new infrastructures in China. The theoretical framework for measuring the size of new infrastructure stock and the results of empirical analyses proposed in this study can provide a theoretical basis and data support for any potential research on the spatial and temporal analysis of new infrastructure construction.

Key words: new infrastructure, stock size, capital stock, physical quantity, balanced and adequate regional development