USA - Although many Americans may have wondered just how much money Mitt Romney makes and how much he pays in taxes in the lead-up to the release Tuesday of his tax documents, there was little suspense around how much he gives to his church.
That's because all Mormons in good standing with the Church of Jesus Christ of Latter-day Saints are required to give 10% of their salaries as a tithe.
"Mormon children are expected to begin tithing from their very first allowance," says Terryl Givens, an expert on Mormonism at the University of Richmond. "And there's never any variation on the 10%, whether you're on welfare or you're a millionaire."
Mitt Romney and his wife, Ann, gave even more to their church last year. Tax documents released Tuesday show they gave $2.6 million, more than 12% of the roughly $21 million they earned. The Romneys also gave $1.4 million last year in cash and stock to their family foundation, which heavily supports the LDS Church.
In 2010, the other year for which the Romneys released a federal tax return, they gave $1.5 million to the LDS church, 7% of their earnings, plus $900,000 to their family foundation, called the Tyler Foundation.
The Tyler Foundation gave $145,000 to the LDS church in 2010, so the Romneys' church donations average out to 10% over the last two years.
Unlike in most Christian traditions, in which the decision about whether to tithe is made individually by each church member, giving to the LDS Church is enforced. Participation in important ceremonies at Mormon temples is contingent on being paid up.
"For Mormons, tithing is an article of faith, not an economic principal," said Givens, who is Mormon. "Some critics see it as tying worthiness to an economic contribution."
He calls it "an important differentiator between devout Mormons and nominal Mormons."
A survey of American Mormons released earlier this month by the Pew Forum on Religion and Public Life found that eight in 10 say they tithe to the church.
Tithing dates back to the earliest Mormons, with the LDS Church's 19th century founder, Joseph Smith, drawing on the Bible's Old Testament as precedent for 10% church support. Smith also wrote about tithing in the Doctrine and Covenants, a Mormon holy book comprising Smith's revelations from God.
For early Mormons, tithing was as much practical as theological. As the early Mormon community journeyed from state to state across America, often on the run from persecution, tithing was an important way for the community to sustain itself.
"Early Mormons were outcasts from society and suffered extreme deprivation and they needed to take care of themselves and take care of the church on a day-to-day basis," Givens said. "To this day, Mormons are known for taking care of their own."
Today, tithing finances the administration of the Salt Lake City, Utah-based LDS Church, the construction of Mormon temples - which are rapidly proliferating as Mormonism grows worldwide - and the church-owned Brigham Young University.
Mormons are also encouraged to give separately to their local congregations and to a church humanitarian fund that goes to international relief projects. The church urges Mormons to fast on the first Sunday of each month and to donate the cost of the food they would typically eat to the humanitarian fund.
An informal 2011 survey by the National Association of Evangelicals found that most evangelical leaders on its 100-person board of directors don't believe the Bible requires tithing. Just 42% of the board members said that is true.