Over 80 countries favour a specific religion, either officially as a state religion or tacitly through special treatment, according to a new report by the US-based Pew Research Center.

Islam is the most common state religion – 27 countries have it as their official religion, including 16 of the 20 countries in the Middle East-North Africa region – while 13 countries have Christianity or a specific Christian denomination as their official religion.

A further 40 countries “favour” a particular religion, according to Pew, through legal, property or tax benefits, or through punishing minority religious groups more harshly. Meanwhile, a further 10 countries treat religion with “hostility” – China, Cuba, North Korea, Vietnam and the six former Soviet countries in Central Asia (Azerbaijan, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan).

In the Middle East-North Africa region, Lebanon is unique as having neither an official religion, nor one it tacitly favours. Of the three other countries there that don’t have Islam as their state religion, Pew says Syria and Turkey tacitly “favour” Islam, while Israel is the world’s only officially Jewish nation.

Buddhism is the official state religion in just two countries – Bhutan and Cambodia – but four more “favour” it – Myanmar, Laos, Mongolia and Sri Lanka.

Hinduism, meanwhile, is not the official religion of any country, but Pew acknowledges the pro-Hindu government in India, and that in 2015 Nepal came close to returning to its roots as a Hindu Kingdom.

Pew highlights the challenges minority groups can experience in countries that have a state religion. It highlights Jordan, where it says converts from Christianity to Islam were “questioned and scrutinised” by security forces, and Iran, where ‘ethnic’ Christians (such as Armenians), Zoroastrians and Jews are the only recognised minority groups, and “public religious expression, persuasion or conversion by these groups is punishable by death”.

Pew also highlights the four states that make adhering to one religion – in each case, Islam – mandatory: the Comoros Islands, the Maldives, Mauritania and Saudi Arabia.

In Saudi Arabia, Pew notes that “conversion from Islam is grounds for charges of apostasy – legally punishable by death”.

“The basic law requires all citizens to be Muslim, and public worship of non-Muslim faiths is prohibited. While non-Muslims are allowed to worship in private, the government does not always respect this right and has raided such meetings of non-Muslims and detained or deported participants,” Pew adds.

Practically, one religion being “favoured” over another may be seen through financial support for salaries, building costs or education.

Pew highlights the example of Turkey, where it says the government has “assigned tens of thousands of students to state-run religious schools known as ‘imam hatip’ schools, while limiting the number of students who can be admitted to public secondary schools. From 2003 to 2015, the number of students in the imam hatip schools rose from 63,000 to about 1 million, and some secular parents have voiced concern that this amounts to heavy-handed government support of religion through education.”

Read the full report here.