Department of Political Science

The Sensitivity of Country Ranks to Index Construction and Aggregation Choice: The Case of Immigration Policy

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  • Liv Bjerre
  • Friederike Roemer, University of Bremen
  • ,
  • Malisa Zobel, Humboldt Viadrina Governance Platform, Municipal Integrat & Dev Initiat

How sensitive are country ranks to the aggregation function used in index construction? This paper tests whether different aggregation functions come to different results in regard to the ranking of countries. Indices within the field of immigration and integration policy are analyzed, yet, the results pertain to index building across the social sciences. The paper discusses three aggregation methods: the arithmetic mean, the geometric mean, and a noncompensatory/non-linear aggregation function based on the Condorcet method. In the empirical part, these three aggregation functions are applied to the family indicators for the year 2010 of the Immigration Policies in Comparison (IMPIC) dataset, a new dataset which measures immigration policies' restrictiveness, as well as to the eight policy strands of the Migrant Integration Policy Index for the year 2014. Results show that the methods react differently to extreme values and thus result in different rank orders in the middle range. In the politicized field of immigration and integration policies, country ranks play a crucial role and this is shown to have profound real-world implications. The paper thus urges researchers to be reflective of the assumptions of different aggregation functions, as these lead to different results.

Original languageEnglish
JournalPolicy Studies Journal
Pages (from-to)647-685
Number of pages39
Publication statusPublished - Aug 2019
Externally publishedYes

    Research areas

  • index building, construction, aggregation method, index country ranks, immigration policy, integration policy, MEASURING DEMOCRACY, INDICATORS, CITIZENSHIP, CONVERGENCE, POLITICS

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