Regulatory Similarity
利用《联邦公报》全文构建公司间监管相似度评分，发现现有相似度指标仅解释其四分之一的变异，但高相似度公司在成本、盈利和投资上同步变动，且主要由财政政策和劳动相关监管驱动。
Using the full text of the Federal Register, the official publication of the US government, we develop a similarity score that compares the regulatory exposure of pairs of companies. A higher score means that the two firms comply with similar regulations by the same regulatory agencies. Existing similarity measures such as industry boundaries, geographic proximity, and product markets account for only one-quarter of the variation in regulatory similarity. Nevertheless, firms with high regulatory similarity comove along key dimensions such as overhead costs, profitability, and investment. Using a supervised machine-learning algorithm, we decompose the similarity into 12 topics and find that it is driven by regulatory issues related to fiscal policy and labor. Each firm has a unique set of peers for each topic, and they all lobby the government on similar topics. Combined, our results uncover economically important links between companies centered around regulatory issues.