This paper draws on a sample of innovative Catalan firms to identify the effects of the two main sources of innovation - internal R&D and external R&D acquisition - on productivity in the manufacturing and service industries. The sample comprises a 3,267 firms from the CIS-4 for the years...

Innovation performance seems to rely on efficiently integrating and extending different pieces of various types of knowledge emerging from diverse external sources. Different research traditions have stressed both formal (FSK) and informal sources of knowledge (ISK) as innovation performance...