Agglomerations, or clusters of businesses in the same area, can boost productivity for firms. A study in Sweden looked at data from manufacturing companies with 10+ employees from 1997-2004. They found that firms in larger regions are more productive, even when considering factors like size, skills, and capital. The study also showed that being in an agglomeration can help firms learn and improve over time. Interestingly, the benefits of agglomeration don't seem to depend on how big a firm is.