 In response, theorists of multiculturalism have called for and collaborated on more empirical research of these purported trade-offs. With respect to the first concern about the tension between diversity and redistribution, Kymlicka and Banting question the generalizability of the empirical evidence that is largely drawn from research either on Africa, where the weakness of state institutions has meant no usable traditions or institutional capacity for dealing with diversity, or on the U.S., where racial inequality has been shaped by centuries of slavery and segregation. Where many minority groups are newcomers and where state institutions are strong, the impact of increasing diversity may be quite different (Kymlicka and Banting 2006, 287). Barbara Arneil has also challenged Putnam’s social capital thesis, arguing that participation in civil society has changed, not declined, largely as a result of mobilization among cultural minorities and women seeking greater inclusion and equality (Arneil 2006a). She argues that it is not diversity itself that leads to changes in trust and civic engagement but the politics of diversity, i.e. how different groups respond to and challenge the norms governing their society. The central issue, then, is not to reduce diversity but to determine principles and procedures by which differences are renegotiated in the name of justice (Arneil and MacDonald 2010).