right|thumb|280px|Change of number of countries in each GPI class from 2007-2009.
The Global Peace Index (GPI) is an attempt to measure the relative position of nations’ and regions’ peacefulness. It is maintained by the Institute for Economics and Peace and developed in consultation with an international panel of peace experts from peace institutes and think tanks with data collected and analysed by the Economist Intelligence Unit. The list was launched first in May 2007 and then in May 2008 and recently on 2 June 2009 and is claimed to be the first study to rank countries around the world according to their peacefulness. The study is the brainchild of Australian entrepreneur Steve Killelea and is endorsed by individuals such as Kofi Annan, the Dalai Lama, archbishop Desmond Tutu, former President Martti Ahtisaari, Muhammad Yunus, economist Jeffrey Sachs, former president of Ireland Mary Robinson and former US president Jimmy Carter. Factors examined by the authors include internal factors such as levels of violence and crime within the country and factors in a country's external relations such as military expenditure and wars.

Methodology

The research team was headed by The Economist Intelligence Unit in conjunction with academics and experts in the field of peace. They measured countries' peacefulness based on wide range of indicators, 24 in all. A table of the indicators is below. In the table, UCDP stands for the Uppsala Conflict Data Program maintained by the University of Uppsala in Sweden, EIU for The Economist Intelligence Unit, UNSCT for the United Nations Survey of Criminal Trends and Operations of Criminal Justice Systems, ICPS is the International Center for Prison Studies at King's College London, IISS for the International Institute for Strategic Studies publication The Military Balance 2007, SIPRI for the Stockholm International Peace Research Institute Arms Transfers Database, and BICC for the Bonn International Center for Conversion.

Indicators not already ranked on a 1 to 5 scale were converted by using the following formula: x=(x-Min(x))/(Max(x)-Min(x)) where Max(x) and Min(x) are the highest and lowest values for that indicator of the countries ranked in the index. The 0 to 1 scores that resulted were then converted to the 1 to 5 scale. Individual indicators were then weighted according to the research team's judgment of their importance. The scores were then tabulated into two weighted sub-indices: internal peace, weighted at 60% of a country's final score, and external peace, weighted at 40% of a country's final score.

The main findings of the Global Peace Index are:

• Peace correlated to indicators such as income, schooling and the level of regional integration (source and numerical coefficient?)

• Peaceful countries often shared high levels of transparency of government and low corruption

• Small, stable countries which are part of regional blocks are most likely to get a higher ranking.

Statistical analysis was applied to discover more specific drivers of peace. Specifically, the research team looked for indicators that were included and excluded from the index that had high levels of correlation with the overall score and rank of countries. Among the statistically significant indicators that were not used in the analysis were the functionality of a country's government, regional integration, hostility to foreigners, importance of religion in national life, and GDP per capita.

Notably absent from the 2007 study are Belarus, Iceland, many African nations, Mongolia, North Korea and Afghanistan. They were not included because reliable data for the 24 indicators was not available.

Criticism and response to criticism

The Economist, in publishing the index, admitted that, "the index will run into some flak." Specifically, according to The Economist, the weighting of military expenditure "may seem to give heart to freeloaders: countries that enjoy peace precisely because others (often the USA) care for their defense." The true utility of the index may lie not in its specific rankings of countries now, but in how those rankings change over time, thus tracking when and how countries become more or less peaceful.

The Peace Index has been criticised for not including indicators specifically relating to violence against women and children. Riane Eisler, writing in the Christian Science Monitor, argued that, "to put it mildly, this blind spot makes the index very inaccurate." She mentions a number of specific cases, including Egypt, where she claims 90% of women are subject to genital mutilation and China, where, she says, "female infanticide is still a problem," , according to a 2000 UNICEF study."

The Index has received endorsements from a number of major international figures, including the former Secretary-General of the United Nations Kofi Annan, former President of Finland and most recent Nobel Peace Prize laureate Martti Ahtisaari, the Dalai Lama, archbishop Desmond Tutu, Muhammad Yunus and former United States President Jimmy Carter. Steve Killelea, the Australian philanthropist who conceived the idea of the Index, argues that the Index "is a wake-up call for leaders around the globe.".

Global Peace Index rankings

Nations considered more peaceful have lower index scores. Countries with rankings in green are in the most peaceful 20% for that year; those in red are in the bottom 20%.

Note: There have been changes to the methodology for the 2009 data.

See also

• Peace

• War

• Anti-war