Offensive - Economic model and natural experiment

Innovation rate is not the highest when first innovators have monopolistic control

Weighted means of annual rates of innovation by phase
Monopoly Entry Balance Shakeout Mature Innovation rates during product life-cycle phases
Rate of all innovations 0.39 0.57 0.62 0.36 0.43
Rate of major innovations 0.19 0.29 0.22 0.18 0.22
Rate of net firm entry 0.22 5.05 -0.07 -4.97 0.16

Source : M. Gort and S. Keppler - "Time paths in the diffusion of product innovation", The Economic Journal, v. 92, 1982

R&D spendings (with respect to sales) have decreased among largest patent holders

Real R&D / Real Output (Deflated R&D Intensity

Source: NBER R&D Masterfile, Annual Reports.