 There are two distinct concerns here. The first is that the existence of racial and ethnic diversity reduces social trust and solidarity, which in turn undermines public support for policies that involve economic redistribution. For example, Robert Putnam argues that the decline in social trust and civic participation in the U.S. is strongly correlated with racial and ethnic diversity (2007). Rodney Hero has shown that the greater the racial and ethnic heterogeneity in a state, the more restrictive state-level welfare programs are (Hero 1998, Hero and Preuhs 2007). Cross-national analyses suggest that differences in racial diversity explain a significant part of the reason why the U.S. has not developed a European-style welfare state (Alesina and Glaeser 2004). The second concern is that multiculturalism policies themselves undermine the welfare-state by heightening the salience of racial and ethnic differences among groups and undermining a sense of common national identity that is viewed as necessary for a robust welfare state (Barry 2001, Gitlin 1995, Rorty 1999).