In Germany, the productivity of professional services, a sector dominated by SME, declined by 40 percent between 1995 and 2014. Similar developments can be observed in several other European economies. Using a German dataset with 700,000 firm-level observations, we analyze this largely undiscovered phenomenon in professional services, the fourth largest sector of the business economy in the EU-15, which provides important inputs to the economy and has experienced substantial growth in both output and employment since the turn of the millennium. We find that changes in the value chain explain about half of the decline and that increases in part-time employment account for another small part. Contrary to expectations, the entry of micro and small firms is not responsible for the decline, despite their lower productivity levels. Further, we cannot confirm the conjecture that weakening competition has led to an increase in the number of unproductive firms remaining in the markets and that this has led to a lower average productivity.

在德国，以中小企业为主的专业服务部门的生产力在 1995 年至 2014 年间下降了 40%。在其他几个欧洲经济体中也可以观察到类似的发展。我们使用包含 700,000 个企业级观察的德国数据集，分析了专业服务中这一在很大程度上未被发现的现象，这是欧盟 15 国商业经济的第四大部门，它为经济提供了重要的投入，并且在两个产出方面都经历了大幅增长和千年之交以来的就业。我们发现价值链的变化解释了大约一半的下降，而兼职就业的增加占了另一小部分。与预期相反，微型和小型企业的进入并不是下降的原因，尽管它们的生产力水平较低。更远，