With the change of organized crime activities in legitimate business through the creation of legitimate companies, most of the countries, among which Italy, introduced specific regulation to fight and weaken the financial basis of OC. However, despite the growing literature on the OC economic impact and the OC companies’ characteristics, some aspects are still not investigated. The present Ph.D.’s thesis reviews the evolution of OC and the law, focusing of literature effort in Chapter 1 and identifying the research questions, drawn up in the following chapters. In Chapter 2, applying a microeconomic theory, I study how the OC infiltration in legal business makes the operation of such companies more profitable, establishing a comparison with legal ones. The theoretical model developed focuses on OC effort during productive activities. In Chapter 3 I evaluate the causal effect of judicial administration on a sample of Italian criminal firms in the period 2004-2016 to shed light on the dynamic path of the firm’s performance from pre-seizure to post-seizure phase. The results reveal that being under measure has adverse effects on the profitability and efficiency level with an increment in the leverage level. The evidence suggests that removing criminal ties makes challenging for the new administrator to maintain profitability and efficiency level. In Chapter 4, I analyze the indirect economic effects of an enforcement law targeting firms affiliated to criminal organizations in the four regions in the South of Italy. The experimental design allows the control for confounding effects at the firm, market, and year level. The results indicate that there are significant positive spillovers from the enforcement law. Legal firms’ performance and turnover rise by 2.2 and 0.7 percent, respectively, in the first four years after an organized crime firm is placed under judicial administration. Investments measured by tangible and intangible assets increase with the number of firms entering into judicial administration by 0.75 percent.