Czarnitzki, Dirk; Kraft, Kornelius; Thorwarth, Susanne - In: Economics Letters 105 (2009) 1, pp. 141-143
Many studies investigate the relationship between R&D and patents applying knowledge production functions. Using aggregated R&D may underestimate the productivity of 'R', as mainly 'R' but not 'D' leads to patents. Disaggregating 'R' and 'D' shows a significant premium of 'R' towards patenting.