Gains and pains from the open innovation framework While firms increasingly adopt open innovation little is known about whether firms gain or lose from this innovation approach. Motivated by this research gap in the literature the thesis explores the antecedents and performance implications of open innovation strategies particularly collaboration and contractual forms of relationships for innovation (i.e. innovation cooperation and R&D outsourcing external R&D). The thesis is empirical and relates the various results to the data used. The first one with German Community Innovation Survey (CIS) the second one with Danish CIS and the third one with the patent enhanced German CIS. The empirical analyses suggest that a value enhancing objective rather than a cost minimization purpose is the main factor that stimulates companies to engage in open innovation strategies. The research also reveals that firms engage in various innovation strategies simultaneously (i.e. international external R&D innovation cooperation partnerships and internal R&D) but they fail to combine these instruments successfully for product innovation implying that the single innovation strategy is performing better than combining different knowledge sourcing strategies in open innovation. Furthermore the thesis provides evidence that sourcing R&D inputs from a domestic R&D provider can be a risky strategy when a firm aims to generate breakthrough product innovations. Instead the firm should seek to acquire knowledge inputs from international marketplaces. The research also indicates that those firms outsourcing R&D activities are more likely to generate inventions than their counterparts that do not invest in this R&D strategy. However this positive performance implication of R&D outsourcing does not appear to hold for invention quality.