Quality of communications infrastructure, local structural transformation, and inequality
利用美国各县互联网速度差异和ARPANET历史数据，研究发现互联网速度翻倍使四年就业增长3.3-6.1个百分点，推动经济转向高技能服务业并加剧不平等。
Abstract We estimate the causal impact of communication infrastructure quality on growth and structural transformation. We use variation across US counties’ Internet speeds in 2018 and build an instrument using ARPANET, a military network that preceded the modern Internet, with its location documented in historical government reports. We find that doubling Internet speeds increases the 4-year employment growth by 3.3–6.1 percentage points. Faster Internet shifts economic activity toward high-skilled services and away from non-tradeable services while increasing inequality. Industry linkages, capital-skill complementarity, and information and communication technology workers’ sorting rationalize our results. Medium and small cities and rural areas drive our results.