<title>Abstract</title> We develop a R&D-based growth model with productive public expenditure in order to frame the Quadruple Helix (QH) innovation concept, based on four helices: <italic>Academia & Technological Infrastructures</italic>, <italic>Firms</italic>, <italic>Government</italic> and <italic>Civil Society</italic>. Our motivation stems from acknowledgment that the...

Multidisciplinary innovation is the main engine of growth for an increasing number of economies. Innovation requires the participation of and interaction between all economic agents. It also requires public spending on education, research and infrastructures. Our main goal is to emphasize the...