Domestic and International Common Language Database (DICL)

The database contains index measures of linguistic similarity both domestically and internationally. The domestic measures capture linguistic similarities present among populations within a single country while the international indexes capture language similarities between two different countries. The 8 indices reflect three different aspects of language: common official languages, common native and acquired spoken languages, and linguistic proximity across different languages. This database has many uses, such as in models of bilateral flows—including FDI, migration, and international trade—as well as in regional or country level analyses. 

Extensive and detailed coverage

  • Bilateral indexes for 242 countries
  • Based on 6,674 individual languages

Download the dataset

The database is available as a single comma-separated (csv) file (6.09MB). The first line of the file contains variable names.  

DOWNLOAD LINK for the DICL database

DICL README file

Technical description

Recommended citation

Gurevich, T., P.R. Herman, F. Toubal, and Y.V. Yotov, (2024), “The Domestic and International Common Language (DICL) Database,” USITC Economics Working Paper 2024–03–A.

Update notes

  • March 2024: Introduced 5 additional language indices to database; added coverage of several additional languages to existing indices; relabeled several existing indices; and removed one redundant index (CL), which can readily be constructed from remaining indices as 0.5*(CNL+LPN).
  • March 2021: DICL first released.

Related research

Gurevich, Tamara, Peter Herman, Farid Toubal, and Yoto Yotov, (2021), “One Nation, One Language? Domestic Language Diversity, Trade and Welfare”, USITC Economics Working Paper 2021–01–B.

Prior versions

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