May 26, 2025 // Local

Researchers Find Link Between Papal Visits, Fertility Rates

Ann Carey

A University of Notre Dame researcher recently discovered a remarkable legacy Pope St. John Paul II bestowed on Latin America during the pontiff’s 16 visits to the region between 1979 and 1996.

Lakshmi Iyer (Photo by Peter Ringenberg/University of Notre Dame)

Economics Professor Lakshmi Iyer and her colleagues set out to determine how the pope’s visits might have impacted life in 13 traditionally Catholic countries there, and they found that birth rates increased dramatically after the pope visited a region.

Iyer told Today’s Catholic that her specialty is not demographics, and most of her research has been on how to improve life for people in mostly poor countries. Thus, she has focused on the intersection of politics and economics, and that involves the influence of leaders.

For example, in her home country of India, Iyer said Hindus are more permissive on abortion than are Muslims. She conducted research to determine whether the values of a leader influenced the behavior of a community regarding abortion. She found that the number of abortions went down when a Muslim rather than a Hindu was elected as a leader. 

That study prompted Iyer’s interest in how people make fertility and family decisions, an interest she discussed with Catholic colleague Paloma Lopez de mesa Moyano, an economics professor at Emory University in Atlanta. 

Moyano was intrigued by the idea that the religion of a leader can influence the actions of the population, and she wondered what happens when religious leaders themselves speak about family and marriage. Moyano still remembered vividly when Pope John Paul II visited her home country of Columbia, and she knew firsthand that the pope’s visits stayed with the people long afterwards.

“For most people, it’s a once-in-a-lifetime moment to have the pope visit your country,” Iyer observed, and the idea came to her and Moyano to investigate whether a population’s behaviors changed regarding marriage, premarital sex, contraception, and abortion after the pope’s visit. They also engaged the assistance of Vivek Moorthy, economics professor at Holy Cross College, who recently earned his Ph.D. from Notre Dame and who had done research in Brazil.

Pope St. John Paul II visited more than 100 countries during his reign, but the researchers decided to focus on Latin America because those countries are majority Catholic, and the pope made 16 visits to 13 countries there between 1979 and 1996.

This choice of locations was also helpful because demographic and health surveys were available for most of those countries from the United States Agency for International Development that assisted poor countries with such data.

The research team looked at this data for the two years before the pope visited and up to five years after. They also took into account major conflicts and immigration that could impact fertility rates.

They concluded in their working paper, “Religion and Demography: Papal Influences on Fertility,” that in the five years after the pope’s visits, birth rates in those 13 countries went up an additional 220,000 to 251,000 babies. This increase was surprising because fertility rates had been dropping dramatically in Latin America.

Iyer and her colleagues’ paper was the first research paper published by a new program in Notre Dame’s College of Arts and Letters: Notre Dame Population Analytics. The program’s purpose is to foster multidisciplinary work on pressing demographic issues that include poverty, inequality, declining health, family instability, and falling religious participation.

The birth rates increased the most where the pope talked about marriage, contraception, or abortion. Birth rates decreased when he condemned premarital sex.

Iyer explained that “the pope’s presence reminded people of what the Catholic Church stands for,” making Catholicism “very salient” with these high-profile visits. She found it particularly interesting that the birth increase was even higher among non-Catholics, possibly because practicing Catholics were already following the Church’s teachings.

The researchers concluded that seeing the pope in person became the thing to do in these predominantly Catholic countries, and his presence and message made the traditional Catholic teachings stronger and more present in people’s minds, prompting them to conform more to what the Church teaches.

The people probably had heard Church teachings before, Iyer explained, but the message resonated in a different way when the pope, who is so admired and influential, came to deliver it.

“Who the messenger is matters,” Iyer told Today’s Catholic. “It needs to be someone who can reinforce what is important to the culture. You can change social norms by having a predominant leader remind people of what is considered good and acceptable behavior within that society.”