I don't know if voluntary surveys gathering demographic information is par for the course in the travel industry.... (oneikathetraveller.com)
A subset of plan sponsors, associated with 1,622 plans 7, that received ERRP reimbursements and responded to 2012 and 2013 voluntary surveys of plan sponsors that had received such reimbursement, indicated that 26 million enrolled individuals, of which almost 2.6 million were early retirees8, benefited or will benefit from the plan sponsors» receipt of funds. (cms.gov)
In point of fact, Statistics Canada has done quite a bit of research documenting the fundamental flaws associated with voluntary surveys; see Kevin Milligan's guest post as well as this. (worthwhile.typepad.com)