Research on the Evolutionary Characteristics of New Energy Vehicle Industry Policy Integrating BERT and DTM from the Policy Tools Perspective

Analyzing and summarizing the evolution characteristics of new energy vehicle industrial policies can provide reference basis and improvement ideas for optimizing the design of policies. This paper takes the 437 new energy vehicle-related industrial policy documents issued at the national level from 1997 to 2023 as the research object, and analyzes the evolutionary characteristics of industrial policies across three dimensions: policy quantity, policy tools, and policy topics. First, the policy tools are applied to categorize these texts into supply-side, environment-side, and demand-side. Subsequently, for each type of texts, both the BERT model and the DTM model are utilized to extract semantic and thematic features, respectively, and then the distribution of their topic feature words is obtained through dynamic topic modeling, and the trend of the topic intensity is further calculated to examine the evolutionary characteristics of these policies. Finally, based on the above analysis, we put forward optimization suggestions for the new energy vehicle industry policy.