This is the second post on the Pew Forum’s Survey of the American Religious Landscape.  I said I was going to comment on the lack of converts and I eventually will, but this post is going to be about a sampling bias Pew found in their data.

On page 41 of the study Pew noticed that their Latino percentages did not match those found in a study they conducted a year earlier.  They had used different questions which may have introduced some bias but they believed and found by conducting an additional survey that the source of the bias was the lack of immediately bilingual questioners.  The Landscape Survey attempted to conduct interviews in English, if they could not complete the survey the household was contacted again by a Spanish interviewer.  In the fully bilingual surveys the Catholic chunk of the Latino population was 65 and 68%.  In the Landscape Survey it was 58%.  Incoporating those numbers into the total population would boost the Catholic percentage from 23.9 to 25.1%.  This falls in the line with other surveys of the American population that has found Catholic membership holding steady at 25% for the past two decades.

There are some interesting numbers that can be drawn from this error.  Pew stated that Latino respondants who completed the full English survey identified themselves as Catholic only 48% of the time.  According to a Pew Hispanic Survey from 2006 59% of Latino’s can speak English.  By doing some math with these numbers I found that of Spanish-speaking Latino’s 89-98% identified as Catholic.  Now I am willing to acknowledge that I using numbers from multiple surveys and that introduces many problems but as a general statement it can be seen that as Latino’s assimilate they are rapidly losing their Catholic character.

According to the 2006 survey 23% of first generation immigrants spoke English, 88% of second generation, and 94% of third generation.  So with a few caveats we can speak of the Spanish speaking cohort as mainly first generation immigrants and the English speaking cohort as later generations.  What this allows us to see is the disintegration of the ability to pass Catholicism onto the new generations once they have reached America.  Catholics are losing 46-51% of later generation Latinos.