Religion affiliation BHPS Wave 7 and 9
I work with questions on religion and find some inconsistencies. Maybe you can help me in sorting this out.
I compare the BHPS 1997 and 1999 question oprlg1 "Which religion do you regard yourself as belonging to". I've checked the questionnaires for 1997 and 1999 and found out some weird inconsistencies between the questionnaires and what we see in the datasets.
In the 1999 questionnaire, there are 16 religion categories while in 1997 there are 14. This happened because category 04 "Presbyterian/Church of Scotland" in 1997 was divided into two in 1999 - 04 "Church of Scotland" and 05 "Free Church or Free Presbyterian Church of Scotland". Also, category 06 "Episcopalian" was added in 1999.
However, when I look at the data, I see another picture: options 04 "Church of Scotland", 05 "Free Church or Free Presbyterian Church of Scotland" and 06 "Episcopalian" presented in both waves. Also, options "Sikh" and "Other" didn't exist in 1997 but according to the questionnaires both options were presented in both waves.
Also, if we look at the religion distribution in 1997 and 1999, we can see weird changes even if we take into account only those people who participated in both waves. For example, there were 188 Baptist in 1997, which dropped to 85 in 1999.
Do you know what happened with this question between these two waves and why there are differences between the data and the questionaries?