On the productivity advantage of cities
利用法国制造业企业的收入、产量和价格数据，分解收入生产率，发现城市密集区的收入生产率优势主要源于更高的定价而非全要素生产率差异，且高需求/高质量产品是支撑高价格的基础。
Abstract Agglomeration externalities are the key factor explaining the existence of cities and their size. However, while the various micro foundations of agglomeration externalities stress the importance of total factor productivity (TFP), the empirical evidence on agglomeration externalities rests on measures obtained using firm revenue or value-added as a measure of firm output: revenue-based TFP (TFP-R). This article uses data on French manufacturing firms’ revenue, quantity, and prices to estimate TFP and TFP-R and decompose the latter into various elements. Our analysis suggests that the revenue productivity advantage of denser areas is mainly driven by higher prices charged rather than differences in TFP. At the same time, firms in denser areas are able to sell higher quantities and generate higher revenues, despite higher prices. These and other results we document suggest that firms in denser areas are able to charge higher prices because they sell higher demand/quality products. In this respect, two key elements related to this capacity to sell more at higher prices are the degree of vertical differentiation and trade cost, with products characterized by higher vertical differentiation and/or lower trade costs featuring stronger patterns and driving overall results.