thus represent greater diversity. I used the answer categories of the identity item and the
Herfindahl concentration formula to calculate the index for each classroom.2 The EFI
however has the drawback of being ‘colour blind’ in that it cannot distinguish a situation
of an 80% native majority and a 20% ethnic minority from its mirror image (80 % ethnic
minority and 20 % native majority). Being able to distinguish between the two situations
is crucial for this study as it needs to assess the effect of diversity for both all students
and for ethnic majority students in order to test the claims of both the contact and conflict
perspective. Obviously, to test the latter it is important to know what the proportion of
ethnic minority students in the classroom is. I therefore calculated this measure
(henceforth called ethnic proportion) alongside the EFI (henceforth heterogeneity). In
addition, a third measure of diversity was created: the proportion of students born abroad
(henceforth immigrants’ share). Although this measure captures first generation
immigrant children only and can therefore be said to underestimate diversity, it is based
on an item which was phrased in a similar way across countries (“where were you
born?”) which enhances comparability.
I used two class-level conditions as control variables. The first of these -
classroom climate - is the class average of a ready-made index in the database labeled as
‘an open climate for classroom discussion’. Previous research by Torney-Purta (2002) on
the same dataset has shown that this variable is strongly correlated to various civic
attitudes. The second is classroom status, which is the classroom average of social
background. Many studies, particularly those examining neighborhood characteristics,
have pointed to the importance of this contextual condition for a range of civic outcomes
(e.g. Letki, 2008; Oliver and Mandelberg, 2000).
Dependent variables
The two entries in the Cived database that we selected to tap ethnic tolerance and
participation, our outcomes of interest, are both composite indices comprising several
2 This formula is 1 - ∑ ni=1 s2ic (where s2i is the share (s) of group i (i = 1, ...., n) in classroom c. For a
more elaborate explanation of the EFI and illustration with examples, see Green et al (2006: 204, 205).
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