• institutional investors;
  • agency theory;
  • institutional theory;
  • institutional investor heterogeneity;
  • socialization of agency theory

Institutional investors report that they prefer to invest in firms with greater board independence despite the fact that researchers have been unable to demonstrate a link between board independence and firm performance. We investigate whether differences among institutional investors affect these preferences. We find that trading strategies have some effect but that mutual funds—facing the strongest institutional pressures—have significantly stronger preferences for firms with greater board independence than do other types of institutional investors. This suggests that institutional investor preferences for independent boards are at least partially driven by institutional pressures rather than anticipated reductions in agency costs. Copyright © 2013 John Wiley & Sons, Ltd.