Linguistic diversity index

Linguistic diversity index (LDI) may refer to either Greenberg's (language) Diversity Index^[1] or the related Index of Linguistic Diversity (ILD) from Terralingua, which measures changes in the underlying LDI over time.^[2]

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).^[3] The ILD measures how the LDI has changed over time; a global ILD of 0.8 indicates a 20% loss of diversity since 1970, but ratios above 1 are possible, and have appeared in regional indexes.^[4]

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 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.^[5]

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 is listed with an index of 0.000, despite having both French and Haitian Creole 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.

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.

SIL International (2017)[6]

UNESCO (2009)[7]

Rank Country / region LDI 1  Papua New Guinea 0.988 2  Cameroon 0.974 3  Vanuatu 0.973 4  Solomon Islands 0.968 5  Central African Republic 0.959 6  Democratic Republic of the Congo 0.948 7  Benin 0.933 8  Chad 0.933 9  South Sudan 0.929 10  Uganda 0.929 11  Kenya 0.927 12  Mozambique 0.926 13  Liberia 0.917 14  India 0.914 15  Togo 0.905 16  Ivory Coast 0.900 17  Nigeria 0.890 18  Mali 0.873 19  South Africa 0.871 20  Tanzania 0.871 21  Ethiopia 0.862 22  Guinea-Bissau 0.859 23  Ghana 0.858 24  Gabon 0.846 25  Philippines 0.842 26  Sierra Leone 0.841 27  Zambia 0.830 28  Bhutan 0.827 29  Qatar 0.825 30  Republic of the Congo 0.821 31  East Timor 0.819 32  Indonesia 0.816 33  Sint Maarten 0.816 34  Afghanistan 0.790 35  Madagascar 0.789 36  Namibia 0.779 37  Senegal 0.778 38  The Gambia 0.776 39  Iraq 0.761 40  Singapore 0.761 41    Nepal 0.755 42  Pakistan 0.752 43  Thailand 0.752 44  Micronesia 0.751 45  New Caledonia 0.750 46  Angola 0.748 47  Guinea 0.748 48  Guam 0.736 49  Malaysia 0.735 50  Belize 0.721 51  Burkina Faso 0.721 52  Israel 0.719 53  Northern Mariana Islands 0.719 54  Suriname 0.709 55  Caribbean Netherlands 0.707 56  United Arab Emirates 0.707 57  Belgium 0.700 58  Oman 0.698 59  Laos 0.697 60  Bosnia and Herzegovina 0.694 61  Malawi 0.692 62  Saint Martin 0.689 63   Switzerland 0.683 64  Tokelau 0.679 65  Eritrea 0.672 66  Andorra 0.671 67  Bahrain 0.658 68  Monaco 0.652 69  Iran 0.638 70  Fiji 0.632 71  São Tomé and Príncipe 0.630 72  Luxembourg 0.622 73  Kuwait 0.605 74  Canada 0.603 75  Trinidad and Tobago 0.599 76  Zimbabwe 0.597 77  Yemen 0.581 78  Niger 0.571 79  Brunei 0.570 80  Bolivia 0.565 81  Comoros 0.551 82  Georgia 0.550 83  United States Virgin Islands 0.550 84  French Guiana 0.549 85  Wallis and Futuna 0.548 86  Libya 0.538 87  Latvia 0.526 88  Myanmar 0.522 89  China 0.521 90  Guatemala 0.518 91  Antigua and Barbuda 0.515 92  Guyana 0.514 93  Kazakhstan 0.514 94  Egypt 0.512 95  Gibraltar 0.511 96  The Bahamas 0.509 97  Djibouti 0.504 98  Albania 0.503 99  Barbados 0.500 100  British Virgin Islands 0.500 101  Jordan 0.498 102  North Macedonia 0.495 103  Taiwan 0.489 104  Ukraine 0.489 105  Nauru 0.487 106  Cayman Islands 0.475 107  Estonia 0.473 108  Palau 0.470 109  Uzbekistan 0.466 110  French Polynesia 0.463 111  Morocco 0.461 112  Italy 0.460 113  Kyrgyzstan 0.459 114  Marshall Islands 0.457 115  Turkmenistan 0.457 116  Réunion 0.452 117  Sri Lanka 0.446 118  Cyprus 0.444 119  Mayotte 0.438 120  Aruba 0.429 121  Saudi Arabia 0.427 122  Belarus 0.411 123  Netherlands 0.405 124  Lithuania 0.404 125  Botswana 0.397 126  Moldova 0.389 127  Syria 0.363 128  Algeria 0.360 129  Somalia 0.350 130  Turkey 0.345 131  Peru 0.339 132  Germany 0.336 133  United States 0.333 134  Norfolk Island 0.325 135  Bangladesh 0.318 136  Dominica 0.313 137  Sudan 0.307 138  Palestine 0.303 139  New Zealand 0.291 140  Panama 0.287 141  Curaçao 0.285 142  Equatorial Guinea 0.284 143  Russia 0.283 144  Spain 0.276 145  Tajikistan 0.276 146  Australia 0.274 147  Vietnam 0.267 148  Malta 0.255 149  Macau 0.253 150  France 0.252 151  Slovakia 0.247 152  Montenegro 0.244 153  Saint Barthélemy 0.244 154  Austria 0.234 155  Cook Islands 0.232 156  Mauritania 0.228 157  Bulgaria 0.226 158  Sweden 0.226 159  Serbia 0.224 160  Mauritius 0.216 161  Paraguay 0.215 162  American Samoa 0.210 163  Swaziland 0.209 164  Hong Kong 0.205 165  Azerbaijan 0.202 166  Lebanon 0.198 167  Greenland 0.196 168  Niue 0.192 169  Ecuador 0.182 170  Mongolia 0.179 171  Samoa 0.174 172  Finland 0.172 173  Slovenia 0.167 174  Argentina 0.165 175  United Kingdom 0.154 176  Romania 0.153 177  Turks and Caicos Islands 0.146 178  Anguilla 0.141 179  Jersey 0.136 180  Greece 0.123 181  Tunisia 0.122 182  Ireland 0.118 183  Seychelles 0.116 184  Uruguay 0.111 185  Saint Pierre and Miquelon 0.110 186  Mexico 0.106 187  Croatia 0.102 188  Cambodia 0.101 189  Brazil 0.099 190  Liechtenstein 0.092 191  Lesotho 0.091 192  Denmark 0.089 193  Rwanda 0.089 194  Guadeloupe 0.083 195  Bermuda 0.076 196  Czech Republic 0.072 197  Norway 0.067 198  Portugal 0.066 199  Grenada 0.064 200  Puerto Rico 0.060 201  Armenia 0.053 202  Nicaragua 0.052 203  Montserrat 0.050 204  Poland 0.050 205  Martinique 0.043 206  Dominican Republic 0.040 207  Venezuela 0.040 208  Honduras 0.039 209  Chile 0.036 210  Costa Rica 0.036 211  Japan 0.035 212  Hungary 0.033 213  Tonga 0.029 214  Saint Lucia 0.020 215  Tuvalu 0.020 216  Colombia 0.019 217  Kiribati 0.019 218  Jamaica 0.017 219  Saint Kitts and Nevis 0.012 220  Saint Vincent and the Grenadines 0.010 221  South Korea 0.010 222  Burundi 0.007 223  Guernsey 0.007 224  Iceland 0.007 225  El Salvador 0.003 226  Cuba 0.001 227  Haiti 0.000 228  Isle of Man 0.000 229  San Marino 0.000 230  Vatican City 0.000 231  British Indian Ocean Territory 0.000 232  North Korea 0.000

Rank Country / region LDI 1  Papua New Guinea .990 2  Vanuatu .972 3  Solomon Islands .965 4  Tanzania .965 5  Central African Republic .960 6  Chad .950 7  Democratic Republic of the Congo .948 8  Cameroon .942 9  India .930 10  Mozambique .929 11  Uganda .928 12  Gabon .919 13  Côte d'Ivoire .917 14  Liberia .912 15  Angola .901 16  Kenya .901 17  Togo .897 18  Timor-Leste .897 19  Mali .876 20  Nigeria .870 21  South Africa .869 22  Zambia .855 23  Guinea-Bissau .853 24  Philippines .849 25  Bhutan .846 26  Indonesia .846 27  Ethiopia .843 28  Republic of the Congo .820 29  Sierra Leone .817 30  Namibia .808 31  Ghana .805 32  Iran .797 33  Micronesia .792 34  Suriname .788 35  Benin .785 36  United Arab Emirates .777 37  Burkina Faso .773 38  Senegal .772 39  Pakistan .762 40  Malaysia .758 41  Thailand .753 42  Eritrea .749 43  Gambia .748 44  Guinea .748 45  Singapore .748 46    Nepal .742 47  Belgium .734 48  Afghanistan .732 49  Kazakhstan .701 50  Trinidad and Tobago .696 51  Belize .693 52  Oman .693 53  Guatemala .691 54  Bolivia .680 55  Laos .678 56  Kyrgyzstan .670 57  Jordan .666 58  Israel .665 59  Bahrain .663 60  Norway .657 61  Madagascar .656 62  Niger .646 63  Mauritius .641 64  Saudi Arabia .609 65  Qatar .608 66  Fiji .607 67  Nauru .596 68  Latvia .595 69  Italy .593 70  Djibouti .592 71  Moldova .589 72  Sudan .587 73  Yemen .579 74  Georgia .576 75  Andorra .574 76  North Macedonia .566 77  Kuwait .556 78  Comoros .551 79  Canada .549 80   Switzerland .547 81  Cayman Islands .547 82  Austria .540 83  Zimbabwe .526 84  Monaco .521 85  Myanmar .521 86  Malawi .519 87  Egypt .509 88  Syria .503 89  Luxembourg .498 90  Gibraltar .498 91  San Marino .494 92  Ukraine .492 93  China .491 94  Iraq .484 95  Tajikistan .482 96  Estonia .476 97  Morocco .466 98  Brunei .456 99  Equatorial Guinea .453 100  Botswana .444 101  Spain .438 102  Uzbekistan .428 103  Bosnia and Herzegovina .416 104  Belarus .397 105  Netherlands .389 106  Sao Tome and Principe .389 107  Aruba .387 108  Bahamas .386 109  Turkmenistan .386 110  Cook Islands .379 111  Peru .376 112  Azerbaijan .373 113  Cyprus .366 114  Libya .362 115  Serbia .359 116  United States .353 117  Paraguay .347 118  Lithuania .339 119  Bangladesh .332 120  Mongolia .331 121  Panama .324 122  Dominica .313 123  Algeria .313 124  Sri Lanka .313 125  Slovakia .307 126  Turkey .289 127  Russia .283 128  France[note 1] .272 129  Netherlands Antilles .266 130  Ecuador .264 131  Lesotho .260 132  Albania .257 133  Vietnam .234 134  Swaziland .228 135  Bulgaria .224 136  Ireland .223 137  Argentina .213 138  Palestine .208 139  Germany .189 140  Somalia .179 141  Greece .175 142  Slovenia .174 143  Armenia .174 144  Mauritania .172 145  Romania .168 146  Sweden .167 147  British Virgin Islands .167 148  Lebanon .161 149  Hungary .158 150  Cambodia .157 151  Turks and Caicos Islands .145 152  Anguilla .140 153  Finland .140 154  Tuvalu .139 155  United Kingdom .139 156  Mexico .135 157  Liechtenstein .128 158  Australia .126 159  New Zealand .102 160  Uruguay .092 161  Barbados .091 162  Croatia .087 163  Nicaragua .081 164  Guyana .078 165  Palau .077 166  Niue .071 167  Cape Verde .070 168  Czech Republic .069 169  Seychelles .067 170  Grenada .064 171  Poland .060 172  Antigua and Barbuda .057 173  Honduras .056 174  Tokelau .054 175  Dominican Republic .053 176  Denmark .051 177  Costa Rica .050 178  Chile .034 179  Kiribati .033 180  Brazil .032 181  Colombia .030 182  Japan .028 183  Marshall Islands .027 184  Montserrat .026 185  Venezuela .026 186  Portugal .022 187  Saint Lucia .020 188  Iceland .019 189  Malta .016 190  Tonga .014 191  Tunisia .012 192  Jamaica .011 193  Saint Kitts and Nevis .010 194  Maldives .010 195  Saint Vincent and the Grenadines .009 196  El Salvador .004 197  Burundi .004 198  Rwanda .004 199  South Korea .003 200  Samoa .002 201  Cuba .001 202  Haiti .000 203  Saint Helena None 204  Vatican City None 205  Montenegro None 206  Bermuda None 207  Hong Kong None 208  Macau None 209  North Korea None

• Ethnologue
• Linguistic rights
• List of official languages by country and territory
• Number of languages by country
• Cultural diversity

• Terralingua's Index of Language Diversity is 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