This study aims to assess the economic benefits of high-speed broadband within and across neighboring counties in Germany. Utilizing a balanced panel dataset of 401 German counties with data from 2010 to 2015 as well as different panel estimation techniques, we find that an increase in average broadband speed has a significantly positive effect on regional GDP in the average German county. Furthermore, we find that broadband deployment in German counties induces not only substantial economic benefits in terms of direct effects within counties but also positive regional externalities across counties. According to our estimation results, an increase in average bandwidth speed by one unit (1 Mbit/s) induces a rise in regional GDP of 0.18%. This effect is almost doubled if we also take regional externalities into account (0.31%). Moreover, we find that regional agglomeraton effects are of particular relevance for rural counties. Our cost-benefit analysis of subsidies based on conservative estimates suggests efficiency gains, as the total economic per capita benefits (€164) of subsidy programs to encourage broadband expansion exceeded their associated per capita costs (€114).

这项研究旨在评估德国相邻县及县内和县之间的高速宽带的经济利益。利用2010年至2015年的401个德国县的平衡面板数据集以及不同的面板估计技术，我们发现平均宽带速度的提高对德国平均郡的地区GDP产生了显着的积极影响。此外，我们发现，德国各县的宽带部署不仅在县内产生直接影响方面带来了可观的经济利益，而且在各县之间也带来了积极的区域外部效应。根据我们的估计结果，平均带宽速度提高一单位（1 Mbit / s）会导致区域GDP增长0.18％。如果我们还考虑到区域外部性（0.31％），则该影响几乎翻倍。此外，我们发现，区域集聚效应与农村县特别相关。我们基于保守估计的补贴成本效益分析表明，由于鼓励宽带扩张的补贴计划的人均经济总收益（164欧元）超过了相关的人均成本（114欧元），效率得到了提高。