It also appears that belonging to the London cluster made writers substantially more productive. Mitchell finds that the average writer in London saw their productivity go up by 12 percent. By comparison, writers in smaller clusters, in Dublin, Edinburgh, Oxford, and Cambridge, saw no such gains. Furthermore, being part of the London cluster increased the likelihood of an author having their work published in any given year by 24 percent.
Source: Even 18th-Century Creatives Tended to Cluster – CityLab