The Pew Forum on Religion and Public Life said in a study posted on its website that as of 2011, 47 percent of the world's nations and territories "have laws or policies that penalize blasphemy, apostasy (abandoning one's faith) or defamation (disparagement or criticism of particular religions or religion in general)."
Of the 198 countries Pew studied, 32 (16 percent) have anti-blasphemy laws, 20 (10 percent) have laws against apostasy and 87 (44 percent) have legal restrictions on the defamation of religion, including hate speech against members of religious groups.
The study was conducted as officials in Pakistan, India and Greece carried out high-profile blasphemy prosecutions.
A Pakistani court dismissed blasphemy charges Tuesday against Rimsha Masih a Christian teenager accused of burning pages of the Koran, in a case that provoked international outrage and forced Masih and her family into hiding.
Pakistan's blasphemy laws were initially intended to keep religious peace but human rights groups have said the laws permit legal discrimination against religious minorities.
A previous Pew study concluded countries that have laws against blasphemy, apostasy or defamation also are more likely than other countries to have high government restrictions on religion or high social hostilities involving religion.
The finding does not necessarily mean such laws cause more restrictions on religion, Pew said.
"But they do suggest that the two phenomena often go hand-in-hand: countries with laws against blasphemy, apostasy or defamation of religion also tend to have higher government restrictions on religion and higher social hostilities involving religion."