help for rq (Version 1)Carlos Gradín (April 2014)

Ethnic Polarization index, Reynal-Querol (J. of Conflict Resolution, 2002)

Syntax

rq varname [weights] [if exp] [in range]

varname indicates the variable of interest (ex. ethnic group, religion, ...).

fweights, aweights and aweights are allowed; see weights.

Description

rq computes the ethnic polarization index proposed by Reynal-Querol (2002), related to Esteban and Ray (Econometrica, 1994) polarization measure, using either individual data or data aggregated by groups.

Formula

RQ = 1 - sum_i [(.5-pi)^2*pi / .25 ] = 4*sum_i [pi^2*(1-pi)]

where pi is the proportion of members of the ith group. RQ is between 0 and 1.

Saved results

Scalar:

r(rq)

Examples

Example of data: individual

ethnicity	weight
1 2
2 2
2 3
3 1
3 1
3 1

. rq ethnicity [aw=weight]

Example of data: aggregated by groups

ethnicity	weight
1 .2
2 .5
3 .3

. rq ethnicity [aw=weight]

In both cases the result is the same:
. Reynal-Querol index (J of Conflict Resolution, 2002) = 0.8800

For bootstrapping (BC estimates), using saved scalars

cap program drop reyq

program def reyq

rq ethnicity [aw=weight]

end

bootstrap r(rq) , reps(1000): reyq

estat bootstrap

Author

Carlos Gradín
<cgradin@uvigo.es>

Facultade de CC. Económicas

Universidade de Vigo

36310 Vigo, Galicia, Spain.

References

Esteban, Joan Maria and Debraj Ray (1994), On the Measurement of Polarization, Econometrica, 62(4):819-851.

Montalvo, José G. and Marta Reynal-Querol (2005), "Ethnic Polarization, Potential Conflict, and Civil Wars", American Economic Review, 95(3): 796-816.

Reynal-Querol, Marta (2002), Ethnicity, Political Systems, and Civil Wars, Journal of Conflict Resolution, 46(1): 29-54.

Also see

er if installed.