The plant size-place effect: agglomeration and monopsony in labour markets
利用美国和英国数据发现，人口密集地区的工厂平均规模更大，而传统集聚理论预测工厂应更小。作者提出劳动力市场买方垄断理论来解释这一现象，并证明大市场中企业面临更弹性的劳动力供给。
This article shows, using data from both the USA and the UK, that average plant size is larger in denser markets. However, many popular theories of agglomeration-spillovers, cost advantages and improved match quality-predict that establishments should be smaller in cities. The article proposes a theory based on monopsony in labour markets-firms in all labour markets have some market power but that they have less market power in cities-that can explain the stylized fact. It also presents evidence that the labour supply curve to individual firms is more elastic in larger markets, consistent with the monopsony hypothesis.