Two out of three people in the world live in countries with high levels of restrictions on religion, a new Pew Research Center report found.

Sixty-four nations out of 198 countries and territories – about one-third of the countries in the world – analyzed have high or very high restrictions on religion. Though a minority of countries are restrictive, these countries have large populations. That translates to nearly 70 percent of the world’s 6.8 billion people living in countries with high restrictions on religion, which mostly affect religious minorities.

The report, “Global Restrictions on Religion,” by the Pew Research Center’s Forum on Religion & Public Life marks the first quantitative study that uses a large amount of data and sources to measure how governments and private groups encroach on religious beliefs and practices around the world.

Pew studied both government actions, such as constitutional limitations or prohibitions on religious speech, as well as social hostilities by private groups, such as religion-related terrorism and violence between religious groups.

Based on its analysis, the highest overall levels of restrictions occurr in Saudi Arabia, Pakistan and Iran, where both the government and social hostility result in high levels of restrictions on religious beliefs and practices.

However, in other countries, such as Vietnam and China, there are high levels of government restrictions with moderate or low levels of social hostilities. Low levels of government restrictions and high range of social hostilities exist in Nigeria and Bangladesh.

Among all regions, the Middle East-North Africa region has the highest government and social restrictions on religion, while the Americas are the least restrictive region on both measures.

Looking just at the 25 most populous countries, the most restrictive on both measures are Iran, Egypt, Indonesia, Pakistan and India. The least restrictive are Brazil, Japan, the United States, Italy, South Africa and the United Kingdom.

In 75 countries (38 percent), the government limits the freedom of religious groups or individuals to share their faith in an effort to convince people to follow their religion. And in 178 countries (90 percent), religious groups must register with the government for various purposes. However, in 117 countries (59 percent), these registration requirements result in major problems for the faith groups.

The study also found that most countries promise religious freedom in their constitutions or basic laws, but only a quarter fully respect this legal right in practice.

Report conclusions are based on analysis of publicly available information from 16 governmental and nongovernmental organizations – including the United Nations, the U.S. State Department, the U.S. Commission on International Religious Freedom, Amnesty International, the U.N. Special Rapporteur on Freedom of Religion or Belief and Human Rights Watch. The study assesses restrictions in 198 countries and territories, representing more than 99.5 percent of the world’s population.

It covers the two-year period from mid-2006 through mid-2008, and includes two indexes – the Government Restriction Index and the Social Hostilities Index. The study analyzes more than 30 measures of restrictions on religion, 20 of which are based on government actions.

“Global Restrictions on Religion” is part of a larger effort called the Global Religious Futures Project, jointly funded by The Pew Charitable Trusts and the John Templeton Foundation, which aims to increase knowledge and understanding of religion around the world.