Two eras can be distinguished in the history of innovation: the era of the inventor, and the era of the researcher, even if the two overlap partially. During the first era, R&D was somewhat reactive, as the inventor imagined solutions to technical problems, especially in manufacturing (textiles, steel, steam, and railroads). In the second era, R&D is somewhat proactive since it increasingly aims to find new products able to generate revenues. Types of financing also changed between the two eras. During the first era, own savings, family savings and help from friends were the only ways of financing innovation. In the second era, large firms’ self-financing and more recently risk-capital have become more important. Although the share of R&D spending in GDP is closely correlated with private financing (that is, countries where public financing dominates are less innovative), it is expected that public efforts in this direction will increase in the future. JEL Codes: N20, O14, O31