In 2001, a study by Mainwaring, Brink, and Perez-Linanhe found the Freedom Index of Freedom in the World to have a strong positive correlation (at least 80%) with three other democracy indices.
Samas Mainwaring, Brink ja Perez-Linanhe on leidnud, et "Freedom in the Worldi" uuring on tugevas positiivses seoses (vähemalt 80%) veel kolme demokraatiaindeksiga.