Working Paper: NBER ID: w28999
Authors: Nicholas Bloom; Tarek Alexander Hassan; Aakash Kalyani; Josh Lerner; Ahmed Tahoun
Abstract: We identify phrases associated with novel technologies using textual analysis of patents, job postings, and earnings calls, enabling us to identify four stylized facts on the diffusion of jobs relating to new technologies. First, the development of new technologies is geographically highly concentrated, more so even than overall patenting: 56% of the economically most impactful technologies come from just two U.S. locations, Silicon Valley and the Northeast Corridor. Second, as the technologies mature and the number of related jobs grows, hiring spreads geographically. But this process is very slow, taking around 50 years to disperse fully. Third, while initial hiring in new technologies is highly skill biased, over time the mean skill level in new positions declines, drawing in an increasing number of lower-skilled workers. Finally, the geographic spread of hiring is slowest for higher-skilled positions, with the locations where new technologies were pioneered remaining the focus for the technology’s high-skill jobs for decades.
Keywords: new technologies; diffusion; employment; income inequality; job postings
JEL Codes: O31; O32
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| Geographic concentration of new technologies (L63) | Development of new technologies (O39) |
| Development of new technologies (O39) | Job hiring spreads geographically (J62) |
| Technologies mature (O30) | Initial hiring is skill-biased (J24) |
| Technologies mature (O30) | Lower-skilled workers gradually enter job market (F66) |
| Initial development locations (O29) | High-skilled job postings (J68) |
| Low-skilled jobs (F66) | Spread more rapidly than high-skilled jobs (F66) |