Considering the source is valid. What is the source? A Catholic blog? Yep. shocker.
Besty is doing his best to "poison the well." If data analysis is presented by Catholics that in any way contradicts what Besty happens to believe, it must therefore be false.
About the blog
http://nineteensixty-four.blogspot.com/2012/06/reverts-catholics-who-left-and-came.html
Nineteen Sixty-four is a research blog for the Center for Applied Research in the Apostolate (CARA) at Georgetown University edited by Mark M. Gray . CARA is a non-profit research center that conducts social scientific studies about the Catholic Church. Founded in 1964, CARA has three major dimensions to its mission: to increase the Catholic Church's self understanding; to serve the applied research needs of Church decision-makers; and to advance scholarly research on religion, particularly Catholicism. Follow CARA on Twitter at: caracatholic .
Mark M. Gray's bio:
http://cara.georgetown.edu/AboutCARA/gray.html
MARK M. GRAY, PH.D.
Mark M. Gray is the Director of CARA Catholic Polls and a Research Associate at CARA. He has a Ph.D. in Political Science and a M.A. in Social Sciences from the University of California, Irvine.
Methodologically, Mark specializes in survey research, trend analysis, and cross-sectional time-series studies. Some of his recent work at CARA has included national surveys of adult Catholics, surveys for Catholic schools, diocesan-level trend analyses, program evaluations, and Catholic media studies. Academically his research focuses on political culture, political participation, and religion and politics. He has taught courses on Introduction to the Social Sciences, Introduction to Political Science, Societal Issues, and Latino/a Culture in the United States.
As a graduate student he worked as a journalist forThe Orange County Register and as a volunteer editor of ABILITYMagazine, a national publication for people with disabilities.
Mark M. Gray is a published researcher:
http://explore.georgetown.edu/people/mmg34/?action=viewpublications
Articles in journals
The analysis was performed by someone with serious credentials and a public reputation to maintain, not some anonymous blogger. Now, go ahead and accuse me of argument from authority all you like Besty, but it is upon you to prove his analysis is fallacious. He used data independently collected by a respected polling firm (Pew) to analyze retention rates. He works for a prestigious university, and the data are available for you to peruse (linked earlier).