This paper examines how different unionisation structures affect firms? innovation incentives and industry employment. We distinguish three modes of unionisation with increasing degree of centralisation: (1) ?Decentralisation? where wages are determined independently at the firm-level, (2) ?coordination? where one industry union sets individual wages for all firms, and (3) ?centralisation? where an industry union sets a uniform wage rate for all firms. While firms? investment incentives are largest under ?centralisation?, investment incentives are non-monotone in the degree of centralisation: ?Decentralisation? carries higher investment incentives than ?coordination?. Labour market policy can spur innovation by decentralising unionisation structures or through non-discrimination rules.