Data show: Vatican II triggered decline in Catholic practice

By Phil Lawler ( bio - articles - email ) | Jul 28, 2025

Throughout the Western world, Catholic Mass attendance has declined dramatically since Vatican II. That is an established fact. But did the Council—or its aftermath—cause the decline, or was the decline part of an overall cultural trend that the Council could not reverse? That question has prompted lively debate for several decades.

In an interesting new contribution to that debate, the National Bureau of Economic Research (NBER) finds that Vatican II was the cause of the decline. An NBER “working paper, Looking Backward: Long-Term Religious Service Attendance in 66 countries, reports that: “Vatican II, in 1962-1965, triggered a decline in worldwide Catholic attendance relative to that in other denominations.”

Notice the last clause of that sentence. After an exhaustive evaluation of the available date, the NBER dismisses the notion that a worldwide secularizing trend hit all religious institutions more or less equally. Not so, the working paper finds. The decline was particularly acute in Catholic countries; secularization hit Catholics harder than other religious groups.

The NBER findings are noteworthy for two other reasons:

1. The NBER is a heavyweight institution in the field of economic research. Established in 1920, the group has produced thousands of solid studies; its list of affiliated scholars includes more than twenty winners of the Nobel Prize for Economics, and more than a dozen past chairmen of the president’s Council of Economic Advisers.
2. This working paper is a product of economic research, prepared by experts analyzing statistical data. Unlike many other contributors to the arguments about the effects of Vatican II, the NBER authors show no interest in intramural Catholic arguments. They don’t have a dog in that fight.

Numbers cannot tell the whole story about declining Mass attendance, of course. But in their analysis, the NBER authors conclude that the data are “consistent with religion modeled as a club good…and with the view that Vatican II shattered the perception of an immovable, truthholding [sic] Church…” They also make the interesting observation that “Vatican II’s depressing influence on the number of nuns led to a sharp decline in fertility among Catholics because of the loss of childbearing support,” and the collapse of the parochial school system.

The strength of this working paper lies in its sophisticated mathematical analysis of church-attendance data. Its weakness appears when it cites the theories of other authors on why Vatican II led to a decline in Catholic piety. The publication relies too heavily on the work of the late Father Andrew Greeley—who, as the NBER authors acknowledge, insisted that it was the debate over Humane Vitae, “more than any other, that shattered the authority structure” of the Catholic Church.

Setting those issues aside, though—and again, the NBER authors do their best to avoid the intramural Catholic debates—the paper concludes that Vatican II was the event that precipitated the decline. “For our purposes, the main point is that, with Vatican II unanticipated, changes in religious-service attendance rates would not have occurred earlier in anticipation of Vatican II, and the subsequent changes in attendance would have been unanticipated.” Furthermore, “the decline in attendance is specific to Catholicism, to which Vatican II would directly apply.”

(h/t to Rorate Caeli for calling attention to the NBER study.)