Geographic Clustering and Productivity: An Instrumental Variable Approach for Classical Composers

It is difficult to estimate the impact of geographic clustering on productivity because of endogeneity issues. I use birthplace-cluster distance as an instrumental variable for the incidence of clustering of prominent classical composers born between 1750 and 1899. I find that geographic clustering strongly impacts the productivity of the clustering individuals: composers were approx. 33 percentage points more productive while they remained in a geographic cluster. Top composers and composers who migrated to the cluster are the greatest beneficiaries of clustering. The benefit depends on the clustering intensity and has a long-term impact.