Immigrant Inclusion Index (IMIX) is a quantitative tool for measuring the electoral inclusion of immigrants in 20 EU member states for 2010. The index includes both de jure (outputs) and de facto (outcomes) indicators. The jure strand assesses the laws regulating the immigrants’ access to citizenship and alien voting rights. Therefore, under de jure indicators, access to citizenship (ius soli, naturalization, and toleration of multiple citizenship for immigrants) and alien enfranchisement (active suffrage for non-citizen residents in legislative and presidential elections, and referend – national and local level) are included. De jure indicators are drawn from EUDO Citizenship Law Indicators. Within the de facto dimension the authors measure the citizenship rate, the naturalization rate, and the alien enfranchisement rate.
Data are harmonized and the measurement level is ordinal and ranges from 0 (theoretical minimum) to 100 (theoretical maximum). To aggregate the components in the respective dimensions, they applied the arithmetic mean. Finally, the authors aggregated the de jure and the de facto dimension by applying the geometric mean.