This paper contributes to the empirical literature on agglomeration economies by measuring the geographic extent of agglomeration externalities and testing for organizational agglomeration economies. It uses a unique database and mapping software to assess how agglomeration benefits decline with distance and how industrial organization affects these benefits. The study finds that agglomeration economies rapidly attenuate within the first few miles but slow down thereafter. It also shows that industrial structure and corporate organization influence the benefits of agglomeration, with small establishments having a greater impact on productivity than larger ones. The paper highlights the importance of location and industrial organization in determining the value of agglomeration. The results suggest that agglomeration should be studied at a more refined geographic level than previously done. The study also finds that the effects of subsidiary status on agglomeration are mixed, indicating that hierarchical corporate structures may not be a reliable measure of agglomeration benefits. Overall, the paper emphasizes the importance of both geographic and organizational factors in understanding agglomeration economies.This paper contributes to the empirical literature on agglomeration economies by measuring the geographic extent of agglomeration externalities and testing for organizational agglomeration economies. It uses a unique database and mapping software to assess how agglomeration benefits decline with distance and how industrial organization affects these benefits. The study finds that agglomeration economies rapidly attenuate within the first few miles but slow down thereafter. It also shows that industrial structure and corporate organization influence the benefits of agglomeration, with small establishments having a greater impact on productivity than larger ones. The paper highlights the importance of location and industrial organization in determining the value of agglomeration. The results suggest that agglomeration should be studied at a more refined geographic level than previously done. The study also finds that the effects of subsidiary status on agglomeration are mixed, indicating that hierarchical corporate structures may not be a reliable measure of agglomeration benefits. Overall, the paper emphasizes the importance of both geographic and organizational factors in understanding agglomeration economies.