The philosophy of law is to reduce transaction costs and control externalities, but the high volume of operational cost laws brings with it a high level of adaptation and supervision. In the implementation of these laws, the volume of government can also increase. The main goal of the present research is to investigate the role of law and regulation production on the size of the government in Iran from 1980 to 2020. In the selected model, the dependent variable is the ratio of total government budget expenditures to gross domestic product. The results indicate that, considering the short-term and long-term coefficients, the law production index, in the presence of other moderating variables, significantly explains the increase in the size of the government in Iran after the revolution.

The analysis shows that the proportion of law and regulation production centers in the country can be deduced from descriptive analysis. This has led to an increase in the influence of decisions made by high courts, administrative justice, and legal complaints, especially in the final decade of the review period. This increase has occurred simultaneously with a decrease in the quality of laws due to the increase in the average size of each law (articles and clauses). Consequently, the legal structure of the country has resulted in increased complexity of laws and reduced transparency.

In conclusion, it can be inferred that the structure of law and regulation production in the country in recent decades has led to increased government intervention in economic and supra-economic mechanisms, which has been accompanied by an increase in the size of the government.