A comparative study on the differences of factors aggregating ability among urban agglomerations in the yangtze river economic belt

：As the main spatial carrier of regional development, urban agglomerations play an increasingly important role in regional development competition. This study took five urban agglomerations in the Yangtze River Economic Belt as the research object and used the Internet big data and other means to analyze their differences of factors aggregating ability and spatial patterns of factors aggregation. The main conclusions are as follows: 1) The difference in the factors aggregating ability between urban agglomerations in the Yangtze River Economic Belt is very significant. This difference is consistent with the regional differences in the level of social and economic developments within the Yangtze River Economic Belt. The agglomeration pattern of factors is characterized by a gradient from east to west. 2) The difference in factors aggregating ability between cities shows the characteristics of polarization, and the core-periphery spatial structure of factors agglomeration of the urban agglomerations is distinct. 3) In the Yangtze River Economic Belt the spatial agglomeration patterns of factors such as technological innovation, opening up, and finance show clear differentiation and centralized distribution features. 4) The rank-size structure distribution of factors aggregating ability of the five urban agglomerations in the Yangtze River Economic Belt is in line with the Zipf's law, and can be divided into two types: balanced and discrete. The relationship between the primacy ratio of urban agglomeration and factors aggregating ability of urban agglomerations presents a relationship of "high at both ends and low in the middle".