
Linguistic diversity index (LDI) may refer to either
Greenberg's (language) Diversity Index
or the related Index of Linguistic Diversity (ILD) from
Terralingua, which measures changes in the underlying LDI over time.
Greenberg's Diversity Index (LDI) is the probability that two people selected from the population at random will have different
mother tongues; it therefore ranges from 0 (everyone has the same mother tongue) to 1 (no two people have the same mother tongue). The ILD measures how the LDI has changed over time; a global ILD of 0.8 indicates a 20% loss of
diversity
Diversity, diversify, or diverse may refer to:
Business
*Diversity (business), the inclusion of people of different identities (ethnicity, gender, age) in the workforce
*Diversity marketing, marketing communication targeting diverse customers
* ...
since 1970, but ratios above 1 are possible, and have appeared in regional indexes.
The computation of the diversity index is based on the population of each language as a proportion of the total population. The index cannot fully account for the vitality of languages. Also, the distinction between a language and a
dialect
A dialect is a Variety (linguistics), variety of language spoken by a particular group of people. This may include dominant and standard language, standardized varieties as well as Vernacular language, vernacular, unwritten, or non-standardize ...
is fluid and often political. A great number of languages are considered to be dialects of another language by some experts and separate languages by others. The index does not consider how different the languages are from each other, nor does it account for second language usage; it considers only the total number of distinct languages, and their relative frequency as mother tongues.
A few examples may be helpful in understanding these caveats.
Are Cantonese and Mandarin Chinese considered the same language for this survey? A footnote in the UNESCO report says only "Country for which a comparison between Ethnologue’s official language designation and IBE’s coded timetable information was possible, the result of which highlighted certain inconsistencies."
Haiti
Haiti, officially the Republic of Haiti, is a country on the island of Hispaniola in the Caribbean Sea, east of Cuba and Jamaica, and south of the Bahamas. It occupies the western three-eighths of the island, which it shares with the Dominican ...
is listed with an index of 0.000, despite having both French and
Haitian Creole
Haitian Creole (; , ; , ), or simply Creole (), is a French-based creole languages, French-based creole language spoken by 10 to 12million people worldwide, and is one of the two official languages of Haiti (the other being French), where it ...
as official languages.
The United States is listed with an index of 1/3, which mechanically implies that if you pick two people at random, at least 1/3 of the time one of them won't have English as their Mother tongue -- but that is very different from saying that they are not fluent in English.
Rankings by country
The UNESCO report cites an earlier (2005) edition of the Ethnologue as its own source for this particular data. The UNESCO report remains a useful independent source and benchmark year because of its wider availability. Footnotes do warn that the precise numbers should be used with some skepticism.
See also
*
Ethnologue
''Ethnologue: Languages of the World'' is an annual reference publication in print and online that provides statistics and other information on the living languages of the world. It is the world's most comprehensive catalogue of languages. It w ...
*
Linguistic rights
*
List of official languages by country and territory
*
Number of languages by country
This is a list of countries by number of languages according to the 22nd edition of Ethnologue (2019).
Languages of Papua New Guinea, Papua New Guinea has the largest number of languages in the world.
Number of living languages and speakers
...
*
Cultural diversity
Notes and references
Notes
References
External links
Terralingua's Index of Language Diversityis a dead link, but similar information is available from the same site at
* https://web.archive.org/web/20120822015417/http://www.terralingua.org/linguisticdiversity/ and it appears to be based on the following paper:
* http://scholarspace.manoa.hawaii.edu/bitstream/handle/10125/4474/harmonloh.pdf
{{Population country lists
Index numbers
Applied linguistics
Language geography