By John L. Allen Jr.

ROME (Crux) — While news agencies and Catholic social media denizens these days gorge themselves on the Vatican’s mounting “Battle of the Books,” seeing who can craft the most sensational headlines or tweets about several controversial new volumes making the rounds, other outfits are, thankfully, still concerned with things that actually matter.

Such is the case, for instance, with the Center for Applied Research in the Apostolate (CARA) at Georgetown University, which, since 1964, has been committed to crunching the numbers about global religion, especially Catholicism.

A Jan. 23 post on a CARA-affiliated blog titled “1964,” edited by Mark Gray, presents data on Mass attendance rates in 36 countries with large Catholic populations. It’s based on the results from the latest cycle of the World Values Survey (WVS), which has studied trends in values in almost 100 countries since 1981.

Unsurprisingly, the central finding is that Mass attendance is much higher in the developing world, especially in Africa.

In Nigeria, a reported 94% of Catholics say they attend Mass at least weekly, followed by Kenya at 73%. Lebanon clocks in at a robust 69% and the Philippines at 56%. By way of contrast, the highest percentage anywhere in Europe is in Poland, at 52%, and in Western Europe, the best performer is Italy, at 34%.

The WVS study also asks people to say whether they consider themselves “religious,” independent of how often they attend religious services, and the CARA blog notes the two things do not always correlate — large percentages of Lebanese say they go to Mass, for example, but the share of Catholics considering themselves “religious” is no more than in the UK.

A better correlation, according to the CARA analysis, is between both Mass attendance and religiosity on the one hand and per capita gross domestic product on the other. With a couple of striking exceptions, the poorer a country is, the more vibrantly religious it’s likely to be.

(Those exceptions include Brazil, where Mass attendance is lower than what one would expect given per capita GDP, and Italy, where it’s higher.)

“The precise mechanisms associated with economic development and wealth that are impacting Catholics’ participation in the faith and identification as religious are unclear,” the report states. “Whatever they are, they matter significantly.”

Just to demonstrate how much this stuff matters, let’s play with the numbers a bit.

First of all, a fun factoid: Based on the WVS data, the prize for the nation with the highest number of regularly practicing Catholics goes to the Philippines, with 47 million, narrowly edging out Mexico with 45.6 million.

Where things really get interesting, however, is in Africa.

Let’s start with Nigeria. Getting accurate religious headcounts there is notoriously difficult, given how religious affiliation is heavily politicized in the world’s largest mixed Muslim/Christian nation. Estimates of the Catholic population range from 20 million all the way to 45 million or higher, but for our purposes, let’s use the Vatican number of 32.5 million.

If 94% of those folks attend Mass once a week, that translates to 30.5 million Catholics.

By way of contrast, the five largest Catholic countries in Western Europe are Italy, Spain, France, Germany, and Portugal. Using the percentages in the WVS data, collectively, they have about 30.4 million Catholics who show up every Sunday.

In other words, Nigeria alone has roughly the same number of regularly practicing Catholics as all of Western Europe.

In reality, the global disparity is much greater than the WVS data suggests because of the relative dearth of sub-Saharan African nations included. For instance, the country with the largest Catholic population in Africa is the Democratic Republic of Congo at 45 million, yet it’s not part of the WVS data set.

If we average Nigeria’s Mass attendance rate and Kenya’s, taking it as a sort of African baseline, it works out to 83.5%. Applying that average to Congo would imply that 37.5 million Catholics attend Mass every Sunday.

(A good share of those 37.5 million folks, by the way, are likely to be in the streets of Kinshasa next week when Pope Francis is in the country for a Jan. 31-Feb. 3 visit.)

Nigeria, Kenya, and Congo together would represent a vast pool of 80 million weekly Mass-goers, which would be about one-quarter larger than the total for all of Europe and North America combined.

Here’s another interesting term for comparison.

The two largest Catholic countries in the world are Brazil and Mexico, with Catholic populations of 123 million and 97 million, respectively. Yet Mexico has a Mass attendance rate of 47% and Brazil just 8%, which means that together, they see about 55.4 million Catholics showing up for church every Sunday.

Nigeria and Congo together, meanwhile, generate 68 million weekly Mass-goers. In other words, Africa’s two largest Catholic nations outperform the two biggest in Latin America by about 20%.

Drilling down, the gap would only grow. Colombia, with Latin America’s highest Mass attendance rate at 54%, has 36 million Catholics, meaning 19.4 million are regularly practicing. Uganda, with a similar Catholic population of 34 million, would produce 28.4 million weekly Mass-goers, or 38% more.

While Catholicism officially numbers around 1.3 billion adherents worldwide, a good share of that total is fairly nominal. In terms of setting the tone within the church, those who are more active generally punch far above their weight — generating a greater share of vocations to the priesthood and religious life, for instance, as well as various lay roles.

In much Catholic parlance, it’s long been said that Africa is the future of the church. Looking at the numbers in terms of who actually shows up, however, Africa isn’t the future. It’s the present, and it has been for a while.