Jason Brennan has posted Diversity for Justice vs. Diversity for Performance: Philosophical and Empirical Tensions on SSRN (here).  The abstract:

Many business ethicists, activists, analysts, and corporate leaders claim that businesses are obligated to promote diversity for the sake of justice. Many also say—good news!—that diversity promotes the bottom line. We … need not choose between social justice and profits. This paper splashes some cold water on the attempt to mate these two claims. On the contrary, I argue, there is philosophical tension between arguments which say diversity is a matter of justice and (empirically sound) arguments which say diversity promotes performance. Further, the kinds of interventions these distinct arguments suggest are different. Things get worse when we examine the theory and empirical evidence about how diversity affects group performance. The kind of diversity which promotes justice and the kind which promotes the bottom line are distinct—and the two can be at odds.