Birth certificates of living persons are usually not publicly available... but some voter records and Copyright Office filings are.
I think you'd be surprised how often publications simply reprint what artists say about themselves without fact-checking and how reluctant they are to correct the record. At least I was. I have a response from a BBC News planning editor that essentially admits that's what they do.
To believe Lana was born in 1986, one would have to believe that she looked unusually old at 18 months, that she began school a year early or skipped a grade, that she (intentionally or not) committed voter fraud in the state of NY, that her listing 1985 as her DOB on her Copyright Office filings and personal Facebook account were just accidents, that various public record searches are wrong as well as every article stating her age before her rise to fame, including a local paper and an article clearly stating that June 21, 2008 was "Lizzy's 23rd birthday" written by a Grant family friend who had done entire cover stories on two men present for the occasion, one of which was her father. One would also have to read nothing into a few early post-recognition articles implying she was yet another year younger (i.e. born in 1987) or her Complex magazine interviewer asking her about her age twice.
Or you can just believe that she and her current management team have been lying about her age.
I believe there's a feedback loop problem here: Several early articles parroted fictitious information given by Lana or her management, Wikipedia based it's DOB on them, tons of later articles repeated the information from Wikipedia, and now Wikipedia won't change their DOB because of the glut of erroneous sources out there. And on and on it goes.
