Abstract The impact of strategies used to appropriate innovation rents on firm performance is analyzed using a sample of U.S. public manufacturing firms. Stronger appropriability at the firm level, achieved through patent protection or the ownership of specialized complementary assets, leads to superior economic performance, as measured by the stock market valuation of a firm's R& D assets. Among commonly used ‘nonconventional’ patent strategies, preemptive patenting allows incumbents to strengthen their market power. Consistent with theory, such effect is higher for incumbents with higher ex ante market power and facing a higher threat of entry, and lower when R& D competition is characterized by the discovery of drastic innovations. Copyright © 2008 John Wiley & Sons, Ltd.