The Democracy Index is an index compiled by the UK based Economist Intelligence Unit, that measures the state of democracy in 167 countries, of which 166 are sovereign states and 165 are UN member states. The index was first produced for 2006, with updates for 2008, 2010 and the following years since then. The index is based on 60 indicators grouped in five different categories measuring pluralism, civil liberties, and political culture. In addition to a numeric score and a ranking, the index categorizes countries as one of four regime types full democracies, flawed democracies, hybrid regimes and authoritarian regimes.
As described in the report, the democracy index is a weighted average based on the answers of 60 questions, each one with either two or three permitted alternative answers. Most answers are "experts' assessments"; the report does not indicate what kinds of experts, nor their number, nor whether the experts are employees of the Economist Intelligence Unit or independent scholars, nor the nationalities of the experts. Some answers are provided by public-opinion surveys from the respective countries. In the case of countries for which survey results are missing, survey results for similar countries and expert assessments are used in order to fill in gaps.
The questions are distributed in the five categories: electoral process and pluralism, civil liberties, functioning of government, political participation, and political culture. Each answer is translated to a mark, either 0 or 1, or for the three-answer alternative questions, 0.5. With the exceptions mentioned below, the sums are added within each category, multiplied by ten, and divided by the total number of questions within the category. There are a few modifying dependencies, which are explained much more precisely than the main rule procedures. In a few cases, an answer yielding zero for one question voids another question; e.g., if the elections for the national legislature and head of government are not considered free (question 1), then the next question, "Are elections... fair?" is not considered, but automatically marked zero. Likewise, there are a few questions considered so important that a low score on them yields a penalty on the total score sum for their respective categories, namely: