We report a puzzling pair of facts concerning the organization of science. The concentration of research output is declining at the department level but increasing at the individual level. For example, in evolutionary biology, over the period 1980 to 2000, the fraction of citation-weighted...

We report a puzzling pair of facts concerning the organization of science. The concentration of research output is declining at the department level but increasing at the individual level. For example, in evolutionary biology, over the period 1980 to 2000, the fraction of citation-weighted...

"Learning-by-doing" is usually identified as a process whereby performance increases with experience in production. The paper investigates different patterns of "learning by doing", studying learning curves at product level. Cost-quantity relationships differ a lot across products belonging to...