Eicher, Theo S., and Thomas Strobel. Information Technology and Productivity Growth: German Trends and OECD Comparisons. Cheltenham, UK: Edward Elgar, 2009. Print.
"Eicher and Strobel have traced the recent US productivity acceleration and the German productivity slump to substantially higher levels of investment in information and communications technology in the United States. They have demonstrated how this investment interacts with the intensity of skills and in research and development to generate productivity growth. This is an important contribution to our understanding of the ongoing divergence of productivity in Europe and the United States."
– Dale Jorgenson, Harvard University, US