1 论文标题
The productivity advantages of large cities distinguishing agglomeration from firm selection
2 作者信息
Pierre-Philippe Combes
Gilles Duranton
Laurent Gobillon
iego Puga and
Sébastien Roux
3 出处和链接（比如，NBER working paper No.11000）
Econometerica，The Econometric Society
4 摘要
Firms are more productive, on average, in larger cities. Two main explanations have
been offered: firm selection (larger cities toughen competition, allowing only the most
productive to survive) and agglomeration economies (larger cities promote interac
tions that increase productivity), possibly reinforced by localized natural advantage. To
distinguish between them, we nest a generalized version of a tractable firm selection
model and a standard model of agglomeration. Stronger selection in larger cities left
truncates the productivity distribution, whereas stronger agglomeration right-shifts and
dilates the distribution. Using this prediction, French establishment-level data, and a
new quantile approach, we show that firm selection cannot explain spatial productivity
differences. This result holds across sectors, city size thresholds, establishment samples,
and area definitions.