Urban areas tend to have much more productive labor and higher salaries than rural areas, and there are vast differences across urban areas. Areas with high salaries and high productivity tend to have employers that invest in much more research and development than areas with low salaries and...

The high-tech sector is increasingly concentrated in a small number of expensive cities, with the top ten cities in "Computer Science", "Semiconductors" and "Biology and Chemistry", accounting for 70%, 79% and 59% of inventors, respectively. Why do inventors tend to locate near other inventors...