Agglomeration economies with consistent productivity estimates

This paper investigates the relative impact of microeconomic agglomeration mechanisms on plant's total factor productivity (TFP) using German establishment and employment-level data. Contrasting different strategies for estimating TFP from plant-level production functions reveals that unobserved output prices bias true productivity and lead to underestimated agglomeration economies. With the corrected TFP measure, the largest impact is found for labor market pooling, which is captured by the correlation of the occupational composition between one county-industry and the rest of the county. This main result is robust, even when the spatial units are resized from counties to larger labor market regions. Input linkages appear to be relevant only at this larger regional scale. Overall, agglomeration economies differ substantially across industries. Only for a subset of industries, some positive evidence is detected for knowledge spillovers.