The subdued wage growth observed in many countries has spurred interest in monopsony views of regional labour markets. This study measures the extent and robustness of employer power and its wage implications exploiting comprehensive matched employer–employee data. We find average (employment-weighted) Herfindhal indices of 800 to 1,100, stable over the 1986–2019 period covered, and that typically less than 8% of workers are exposed to concentration levels thought to raise market power concerns. When controlling for both worker and firm heterogeneity and instrumenting for concentration, we find that wages are negatively affected by employer concentration, with elasticities of around −1.4%. We also find that several methodological choices can change significantly both the measurement of concentration and its wage effects.

许多国家的工资增长乏力，引发了人们对区域劳动力市场垄断观点的兴趣。本研究利用全面匹配的雇主-雇员数据来衡量雇主权力的程度和稳健性及其对工资的影响。我们发现平均（就业加权）赫芬达尔指数为 800 至 1,100，在 1986 年至 2019 年期间保持稳定，并且通常只有不到 8% 的工人面临被认为会引发市场力量担忧的集中水平。当控制工人和企业的异质性并测量集中度时，我们发现工资受到雇主集中度的负面影响，弹性约为-1.4%。我们还发现，一些方法论的选择可以显着改变集中度的衡量及其工资效应。