Five Million Fewer Mainline Protestant Adults Than in 2007
Pew Research Center’s 2014 Religious Landscape Study finds that 14.7% of U.S. adults are affiliated with the mainline Protestant tradition – a sharp decline from 18.1% when our last Religious Landscape Study was conducted in 2007. Mainline Protestants have declined at a faster rate than any other major Christian group, including Catholics and evangelical Protestants, and as a result also are shrinking as a share of all Protestants and Christians.
Indeed, despite overall U.S. population growth between 2007 and 2014, the total number of mainline Protestant adults has decreased by roughly 5 million during that time (from about 41 million in 2007 to 36 million in 2014).
Generational replacement appears to be playing a significant role. Older generations have larger shares of mainline Protestants, including 26% of members of the Greatest generation (those born before 1928) and 22% of members of the Silent generation (those born 1928-1945). Mainline Protestant adults in the U.S. have a median age of 52, higher than the group’s median age in 2007 (50) and older than any other major religious tradition.
Five Million Fewer  | Mainline Protestant  | Adults Than in 2007  | 55 MILLION  | 50  | 45  | 42.1  | 40 41.1 42.1 401 a  | 37.1 36.  | 401  | 37.1 36. 0 Estimate  | 35  | 34.9  | 30  | Range, given  | Range, margin given of error  | a  | 2007  | 2014  | Source: 2014 Religious Landscape  | Study, conducted June 4-Sept. 30, 2014  | PEW RESEARCH CENTER 